Types Of Dam Liners
As a dam liner company, Grekkon Limited supplies and installs 3 types of dam liners in Kenya by thickness, and 2 types of dam liners by material. In this article, we answer many water harvesting using dam liners questions posed to us by growers
1. What type of dam liner is best?
1.1. Types of dam liners in Kenya – by material
High density polyethylene (HDPE) dam liners
This is what we supply and install most. This is because it is thin and lightweight which makes it easy to carry. They are tough with high tensile strength, hard to puncture, and stiff, which makes them less prone to sudden length tears. However, this stiffness makes welding more difficult. HDPE dam liners have the best UV resistance, and are safe for the environment because they do not emit chemicals. Their disadvantage is that they’re more difficult to repair when perforated. Our HDPE dam liners are in rolls from which we cut and tailor weld it to a water pan’s specifications
Polyvinyl chloride (PVC) dam liners
We supply and install these but at a lessor scale. PVC dam liners are highly flexible, impermeable and tough. They are heavier than HDPE dam liners, but easier to weld as the material joins together more easily. They have the best resistance to chemicals and acids and so they are not easily corroded. This makes them the most suitable for land fills and chemical containment sites. Our PVC dam liners are factory fabricated panels that eases installation. The downside with PVC dam liners is environmental safety because they release chemicals as the PVC material degrades. This in the long-term is toxic to fish
Low density polyethylene (LLDPE) dam liners
They are made from the same plastic as HDPE dam liners, and so share similarities. Being less dense than their HDPE cousins, they are softer, more flexible and more pliable. Being softer makes them less susceptible to stress cracking. High flexibility allows for easier under installation, and molding them around corners, nooks and crannies. Pliability means they conform best to rough terrain with little wrinkles
1.2. Types of dam liners in Kenya – by thickness
- 0.5mm / 500 microns. This is for smooth surfaces and to hold low water volume (5,000 cubic liters and below)
- 0.75mm / 750 microns and 0.8mm / 800 microns. Works well in rough surfaces with few stones or murram. It will hold medium water capacity
- 1mm / 1,000 microns. Best for stony or rocky surfaces, and high capacity
- 1.5mm / 1,500 microns. Works on surfaces that the 1mm will not, and holds ultra high water volumes
2. Which is better: PVC or HDPE dam liner?
HDPE is better because it has greater tensile strength, and does not contaminate the environment
3. What is a good thickness for a dam liner?
The choice of thickness is determined by the surface and water volume. For instance, a 0.5mm dam liner is more appropriate for a concrete water tank holding 100 cubic litres than a 1mm dam liner
4. What are the 2 main types of dam liners?
HDPE and PVC dam liners are the most common dam liners in Kenya
5. How long does a dam liner last?
This depends on the thickness, material type and use. As a guideline though, 0.5mm thick dam liners last to 15 years, 0.75mm to 25 years, and 1mm to 36 years
6. Can I put a new dam liner over an old one?
The simple answer is yes, but remove any liquid, and solid debris on the old liner’s surface. Note that once the new one is placed, you cannot shift the old liner without affecting the new one. The new dam liner is not joined to the old dam liner in any way
7. How often do dam liners need to be replaced?
So long as the dam liner is functioning well, it is unnecessary to remove it. There is no replacement timeline
8. What is the best liner for a large water pan?
Large is relative. But for any water reservoir holding beyond 5,000 cubic litres, we recommend the 0.75mm or the 1mm thick dam liners
9. How do you hold a dam liner in a water pan?
There are 2 ways.
9.1. Trenching
This is where a 2 feet deep by 1 foot wide trench is excavated all round the circumference of the water reservoir. This trench is 0.75M to 1M from the edge of the water pan. The dam liner is tucked in here then covered with soil, gravel or rocks/ stones
9.2. Sand bags
Bags filled with soil, sand or gravel are laid on top of the dam liner edges to anchor it in place
The different types of dam liners does not affect the holding method
10. Can you join 2 dam liners together?
Yes. Pieces of dam liner welded together make a continuous sheet
11. Can you glue 2 dam liners together?
The best way to join dam liners is by welding because it is permanent
12. Can you cut a dam liner?
Yes. We cut and weld together dam liner sheets from large rolls to tailor it to the water pan’s dimensions
13. Can you put gravel on top of a dam liner?
Yes you can especially if it is for support on the edges
What to consider when choosing a dam liner
- The surface texture. Install a thicker liner for rougher surfaces
- Water volume. The larger it is, the thicker the dam liner
- Purpose. If it will hold chemicals or acids, then the PVC dam liner is best because it is the most resistant
Hybrid Solar Dryers For Sale In Kenya
Hybrid solar dryers for sale in Kenya by Grekkon Limited are active dryers designed to dry quicker, all year round. They are augmented units of the conventional passive solar dryers. The company has three types of hybrid solar dryers for sale in Kenya- Solar powered. These units have a solar powering system that runs the extraction and exhaust fans. The fans provide better movement of air within the dryer, and removal of the moisture from the drying produce. This hastens the drying process
- Biomass powered. They have a biomass burning unit connected on the exterior. Biomass in the form of brickettes or charcoal heats water which produces steam that travels in tubes within the dryer. This heats up the air in the dryer, accelerating the dring process. Biomass powered dryers can be used at night or on cloudy, rainy or cold days when there is insufficient sunshine to dry
Hybrid Solar Dryers For Sale In Kenya
Solar Dryer Materials
- Light UV treated translucent polythene paper to allow heat and light. The paper also has anti-drip treatment to prevent dew formation which causes moulds to form on food
- Heavy UV treated geomembrane to conserve heat
- Steel bars galvanized with food-grade aluminum or zinc for food safety
- UV treated heavy gauge netting to prevent insect pests from entering
Hybrid Solar Dryers For Sale In Kenya
I. What is hybrid solar dryer?
It is a conventional solar dryer that receives additional drying power from an external source. This could be biomass, solar or electricityII. What are the three types of solar dryers?
- Natural / conventional solar dryers. These dry using only the power of the sun
- Forced / active dryers. They are augmented versions of the conventional solar dryers
- Portable or fixed solar dryers
III. How does a vegetable dryer work?
- Heat
They allow in diffused heat from the top and the sides, which heats up the air coming in from the air inlet. This hot air will exit with moisture in the air outlet.
- Anti-drip management
Our UV treated polythene cover has anti-drip properties so water droplets do not form on it. It prevents dripping on the drying food which is a precursor for fungal development
IV. What does a solar dryer do?
Grekkon Limited’s solar dryers reduce the moisture content to less than 12% in these products;
- Plantation crops; coffee, rice, cassava
- Vegetables; tomato, onion, garlic, brassicas, hot peppers
- Cereals; sorghum, and millet
- Herbs; moringa, mint, rosemary
- Oil crops; groundnuts, sunflower, macadamia, cashew nuts
- Others; mushrooms, fish, beef, mutton
V. How do you dry vegetables with solar?
- Wash the vegetables to remove all dirt
- Ensure there are no insect pests present
- Remove any diseased parts or produce
- Cut or grind them into smaller pieces to increase the drying surface area
Place them in the solar dryer holding trays
VI. What is the most popular use of solar dryers?
To dry fruits, mushrooms, vegetables, herbs, spices, coffee, cassava, banana and fish. Banana and cassava are further processed into food flour. A solar dryer ensures that the food is free of any external contamination
VII. What are the main applications of a solar dryer?
Besides vegetables and fruits, commercial solar dryers in Kenya are for fish, root crops and mushroom drying. Commonly dried foods in Kenya through our solar dryers are:
i. Banana, cassava, pumpkin, millet, and sorghum to make food flour. Dried cassava is also processed for industrial starch manufacture
ii. Moringa as a medicinal herb
iii. Tomato, capsicum, traditional vegetables, kales, and spinach as vegetable nutrients
iv. Mango, papaya, as dried fruits for snacking
v. Omena which is the silver cyprinid fish for both human consumption, and as additive to animal feed
vi. Coffee so that it’s suitable for milling. Coffee solar dryers are the largest, each holding over 5 tons of berries per drying session
Solar Dryers For Fruits And Vegetables
Grekkon Limited’s hybrid solar dryers for fruits and vegetables in Kenya are designed to dry faster than the conventional or natural solar dryers. They are enhanced with cyclone roof top vents, and fans on the sides. Hybrid solar dehydrators are efficient for large- scale commercial food drying. This is especially with longer to dry fleshy food like; cassava, banana, tomato, fruits, and rice. Drying time is a factor of the food crop type, and the prevailing ambient temperature during the drying period. The quality of the dry produce is consistent. The dryer works through the greenhouse effect.
Solar Dryers For Fruits And Vegetable In Kenya
Solar Dryer Materials
- UV treated paper on the sides and roof. UV block treatment on the polythene paper extends it’s usable lifetime to 4 years. This treatment prevents UV degradation of the food crop. The polythene paper has anti-drip properties to keep dew from forming on the inside of the paper. Dew drops on the drying food will cause molding.
2. Galvanised steel support structure. Galvanised with food grade aluminum, or zinc
3. Concrete floor for the permanent/ immovable models
4. Heat absorbing and releasing dam liner to line the floor
5. Roof top cyclones. Ensures the air is evenly distributed within so that there are no air pockets. This results in evenness of drying for the produce. We install cyclone roof top vents from a particular solar dryer size
6. Fanning system. This comprises of;
- solar panels; to provide electric DC power
- a control box; to regulate electric current
- an inverter; to convert DC energy form the solar panels to AC to power the fans
- fans; an extraction fan to allow push in air, and an exhaust fan to move out accumulated moisture
7. Nets. High density UV treated nets on the air entry and exit points
8. Drying trays designed with material specific to food drying
Every material used is specific to solar dryers for fruits and vegetables to provide; efficiency, safety, and food quality
How To Use Solar Dryers For Fruits And Vegetables
- Chop or slice the produce into smaller pieces. This increases the surface area for drying
- Place these pieces on the drying trays
- Keep the door closed always to avoid food contamination
- Every drying 3 hours, monitor the moisture content using a moisture meter
Solar Dryers For Fruits And Vegetables
FAQs
1. What are the 2 types of solar dryers?
1.1. Passive solar dryers. They only utilise the sun’s warmth
1.2. Active solar dryers. These ar hybrid solar dryers that utilise both passive drying and biomass generated heat
2. How do you make a solar dryer?
Grekkon limited’s low cost solar dryers in Kenya are made from the following materials
2.1. A zinc or aluminum galvanised steel structure. It is rust free and easy to clean with plain water
2.2. UV treated greenhouse polythene with anti-drip properties. The UV treatment prevents food degradation by the sun’s UV rays. It ensures that the color, taste, scent, and nutritional value remains after the moisture is removed. The anti-drip treatment prevents moisture droplets from condensing on the paper and forming drop that will fall on the food. Such drops cause molding
2.3. A heat absorbent floor. his one absorbs heat during the day, and releases it at night reducing tea variance between day and night temperatures. Dew formation and mold development is aggravated by a huge difference between day and night temperatures
2.4. A UV treated heavy gauge insect net to protect the produce from insect pests. This insect net covers the air vents
For a hybrid solar dryer we add all or part of the following
2.5. A biomass combustion chamber with a pipe that carries the heat to into the solar dryer. This one is used at night when there is no sunshine, or on cloudy, cold or rainy days. It ensures continuous drying irrespective of the prevailing weather
2.6. A solar panel with a battery to power cyclones, and extraction and exhaust fan. This system speeds up the drying process by increasing air ,movement withing the solar drying chamber. And also help in evenness of drying in the chamber
3. What is the size of a solar dryer?
Your solar dryer size will be determined by the weight and volume of product dried per session. The larger it is, the larger will be your solar dryer
4. How do I choose a solar dryer size?
Grekkon Limited guides on the solar dryer size a client will need based on the produce type and drying quantity per session
5. What is the mot popular use of a solar dryer?
To cleanly extract moisture (dehydrate) from farm produce, yet retain all other qualities
6. What type of solar dryer is best?
A hybrid solar dryer is the best because it allows for continuous drying; both day and night, and on cloudy or cold days
How To Install Rain Hose Kits
Grekkon Limited’s manual on how to install rain hose kits in Kenya is an easy to read step by step guide. It details every aspect of rain pipe assembly in the farm to provide understanding to farmers. As the pioneer of rain hose kits in Kenya, we are keen to that farmers receive the full benefit of rain pipe irrigation
What is the price of a rain hose irrigation kit?
Diameter size | Flow rate per 100M | Price in KES |
32mm or 1″ | 13 cubic litres per hour | KES 2,500 |
40mm or 1-1/4” | 16 cubic litres per hour | KES 5,800 |
50mm to 1-1/2″ | 22 cubic litres per hour | KES 6,800 |
Rain hose pipes work under high gravity pressure (from 6M or 0.6bar), and with high volume water pumps. The discharge rate of the water pump is from 40 cubic litres per hour. These water pumps are surface solar, electric, petrol or diesel powered
How To Install Rain Hose Kits
- Trench where the poly vinyl chloride (PVC) main line will be laid. This is not necessary for the high density polyethylene (HDPE) which are surface pipes. PVC pipes are sub-surface pipes because they have no UV-treatment, and will thus degrade easily under the sun. HDPE pipes have UV treatment and will be surface pipes
- Connect the PVC or (HDPE) main line to the water pump or high tank. This pipe evacuates water from the source to the farm and is the largest in diameter. The larger the pipe diameter, the more the water it delivers. .
- Join the HDPE or PVC sub-main line to the main line. The sub-main line is smaller in diameter, and so carries less water. It is joined to the main line through PVC or HDPE accessories such as; tees, elbows, saddle clamps, adaptors or valve sockets
- Connect the rain pipe to the sub-main line or the main line where a sub-main line does not exist. This is done with a rain hose connector or a saddle clamp
- Spread the rain hose along the length, and close the terminal end with an end cap
- Connect one rain pipe to another with a connector
A drilling tool is the only tool used when installing a rain hose kit. This is to create an opening on the main or sub-main line to insert the rain pipe ball valve
How to Install Rain Hose Kits
Components of a rain hose irrigation kit?
1. End-caps. They close the end of the pipe to prevent further water flow
2. Starter off-takes. They connect the rain pipe to the PVC or HDPE main line that supplies water to the rain hose from a water pump or highly elevated water tank
3. Pipe connectors. To connect one rain hose pipe to another
4. Mini valves. To control water flow to the rain hose pipe
The diameter of the pipe are; 25mm, 32mm, 40mm and 50mm. A grower chooses the preferred size based on crop water needs and area of irrigation. For instance, a farmer with 1 acre of the crop will comfortably water with the volume delivered through a 32mm rain hose pipe.
Another grower with 5 acres will better irrigate with a 50mm rain hose pipe. An acre of crop uses 1,000 meters of 25mm, 800 meters of 32mm rain hose pipes, 600M of 40mm pipes, and 400M of 50mm pipes
How To Install rain Hose Kits
Rain hose irrigation system requirements
- The system requires a pressure head of 30M, and above
- When using a water pump to power the rain hose irrigation kit, the discharge rate should be from 45 cubic litres per hour
- The rate of water discharge is determined by the diameter size, and number of pores on the rain pipe. For instance, a rain pipe with 5 holes per cluster discharges less water than the one with 7 holes in a cluster
- It irrigates in opposite directions at a radius of 3M for the 32mm pipe, 5M for the 40mm pipe, and 7M for the 50mm pipe
- The vertical height of this water jet is 1M
Rain Hose Versus Drip Irrigation
- Rain pipes irrigate in an overhead fashion, drip lines irrigate to the root zone
- Drip tapes are water efficient, rain hose kits require large water volume
- Rain pipes have a higher pressure requirement than drip pipes
- Drip lines have emitters, while rain hose kits have pores done with nano technology
- The discharge rate for drip lines is 1.2 to 4 litres per hour per emitter, while the rain hose pore’s is from 7 litres per hour per emitter
- The cost of a drip kit installation per acre is from Kes 100,000, while the rain hose is from Kes 75,000
- The rain hose pipe’s minimum diameter is 25mm/ 3/4″, while drip tape’s is 8mm
Advantages Of A Rain Hose
- water saving and cost effective
- It is easy to install, use and maintain
- Ran hose nanotechnology punched holes are less prone to clogging
- It is used in a broad range of crops
- Rain hose pipes are light and easy to move about
- It irrigates uniformly
- It works under both low gravity and high water pump pressure
Rain hose irrigation system is for the following areas and on these crops
- Crop nurseries; vegetables, fruit trees, forestry
- Short vegetable crops (knee-high and below); cabbage, lettuce, broccoli, kales, spinach, collards, broad beans, carrot, strawberry, and others
- Pasture; grass and legumes
When choosing the crop to irrigate using this method, consider its susceptibility to foliage fungal infections predisposed by leaf surface wetness. Tomato, potato, peppers, peas, green beans, and chili easily succumb to foliage fungal infections when overhead or a rain hose system is used for a long time
How To Install Rain hose Kits
FAQs
a. What is the difference between a rain hose irrigation system and a sprinkler system?
- The technology. The rain pipe irrigation system is designed using nano technology
- The mode of spray. A sprinkler sprays its water in one direction, a rain hose pipe sprays in 3 directions (vertically, horizontally, and diagonally)
- Placement. A sprinkler is placed upright on the surface or sub-surface (for pop up sprinklers). A rain hose is laid on the ground
b. What is the pressure in a rain pipe?
The minimum operating pressure is 30M head / 3 bars
c. What is the spacing for rain hose irrigation?
The distance from one rain pipe to another is from 1.5M depending on the operating pressure, and pipe diameter
Grekkon limited is the largest supplier and installer of rain hose irrigation systems in Kenya, and in the east and central Africa region
How To Grow Azolla
When training farmers on how to grow azolla in Kenya using Grekkon Limited’s dam liners, and shade nets, the company offers a detailed session to farmers as documented in this article. Azolla pinnata is the most common variety grown in Kenya
What is Azolla?
Azolla, belonging to the Salvinaceae family is a fresh water aquatic plant. It is a nitrogen fixing, branched free-floating fern also referred to as duckweed, mosquito fern or water fern. Its most popular characteristic is its ability to exponentially grow by doubling its biomass every 3 days depending on the growing conditions. This is why it is regarded as a super plant. Some refer to it as the green gold mine due to its high nutritive value
Benefits of azolla
- it is a green manure because of its nitrogen fixing property
- it reduces weeds
- soil organic carbon is increased which in turn microbial biomass in the soil
- as a livestock feed, its is an economical way of providing affrodable high protein, essential amino acids, and vitamins (A, B12, Beta Carotene) to animals
How to grow azolla in Kenya
Nutrition Requirements
i .Light: Azolla grows well under partial shade. Growth decreases quickly under heavy shade (lower than 1,500 lux) and more than 50% of full sunlight reduces photosynthesis. This is why a shade net cover is necessary where sunlight is intense. It causes it to turn reddish brown, which reduces the nutrient value
ii. Nutrition: for vigorous production, add 20kgs per Ha of phosphorous. Cow dung slurry, and super phospahte fertiliser provides this
iii. Relative humidity : high at 80 – 90 %
iv. Growing PH: lightly acidic media at : 5.2-5.8
v. Temperature: keep it below 25 degrees centigrade for a luxurious growth. Where it exceeds this, provide a shade net cover
vi. Water: fresh water 10-15 cm in the multiplication pond, adequate water level in the pond is 4 inches
Steps on how to grow azolla
- select a pond site in a cool shaded location. Shade minimises evaporation, and encourages rapid growth. Ensure that that the pond site is close to a water source. To produce 1kg of azolla daily, the pond will be 2M (L) x 1.5M (W) x 0.15M (D) in dimension
- line the pond using a dam liner to prevent water loss through seepage into the soil
- add soil mixed with cow dung in the pond. Slurry can also be used. These are mixed with water and spread uniformly in the pond
- add 1kg of azolla culture
How to grow azolla
Maintainance
- add 20g of super phosphate mixed with 1kg cow dung every 5 days to keep it’s growth vigorous
- replace the azolla crop after 6 months
- harvest the crop after 15 days by hand or a plastic scoop, then every 3 days afterwards to avoid overcrowding, and maintaining a large biomass. With good feeding, the yield is 1.5kgs – 1.6kgs every 3 days
- clean it thoroughly to remove the cow dung smell
- dry it or feed it fresh to livestock. It can also be mixed with other animal feeds
How to Grow Azolla
FAQs
1. How profitable is azolla farming in Kenya?
Azolla farming is profitable beacuse of its many uses. It can be grown commercially as;
- livstock feed
- a bio fertiliser
- as propagation material to sell to other farmers seeking to set up azolla growing units
2. What is azolla used for?
As a nitrogenous fertliser, and as an animal feed. It is easily digestible because of its high protein and low lignin content. It increases feed efficiency, daily anaimal weight gain, and milk production by 15% – 20%
3. Why is my azolla turning black?
It first turns brown due to too much exposure to sunlight, high temperatures, lack of nutrients in the pond or fungal / bacterial diseases. Eventually, the crop dies
4. Can azolla survive without sunlight?
No
5. What are the negative effects of azolla?
Azolla shades out other water plants, killing them together with fish and other aquatic animals. Its decay creates a strong odour which affects fish and other aquatic animals
6. What are the limitations of azolla?
It cannot grow in a waterless environment
7. Does azolla repel mosquitoes?
Yes it does by over 95%
8. Does azolla increase eggs production in chicken?
Yes it does because it provides protein, that adds weight to the bird
Multi-Storey Gardens In Kenya
Grekkon Limited’s climate smart agriculture multi-storey gardens in Kenya are a vertical farming system popular with urban vegetable farmers. Growing herbs on a multi-storey garden in Kenya is now a common practice in limited spaces in densely populated locations. They are defined as climate smart agriculture because they conserve land and water
What is a multi-storey garden?
It is a vertical farming method that limited space to create gardens stacked on each other. These vegetable crops (most common for kitchen gardens) provide a fresh supply of vegetables for subsistence or commercial use. Commonly grown crops are;
- Vegetables; kales, spinach, strawberry, coriander, carrot, garlic, leeks, black nightshade, amaranth
- Herbs and spices; rosemary, lemon grass, citronella, and mint
- Fruits; strawberry
A grower will choose to have the multi-storey farming system out in the open, or enclosed in a greenhouse or shade house. This multi-storey cropping is determined by the crop grown, or other factors such as crop destruction by pests or disturbance from pets. A grower will choose to have a shade net or dam liner as the supporting basis of this pyramid farming in Kenya. In this article, we look at the dam liner option
Our multi-storey garden price is Kes 2,500 a unit for the dam liner material type. This multi-storey garden cost covers all material and labor
How do you make multi-storey gardens in Kenya?
Key attributes of the dam liner material type garden
- Layers. It has 6 layers including the base
- Circumference. The base layer has a 6M circumference
- Layer reduction by height. Each layer is a meter less in circumference as it rises
- Height. Each layer has a height of 0.2M / 20cm
- Material. 0.75mm or 1mm thick HDPE dam liner to hold the soil together. The dam liner is bolted or welded at the joint
To reduce soil compaction, and improve soil aeration, we mix soil with manure at a ratio of 2:1. On a space of 2M x 2M, a multi-storey garden will hold 180 to 250 plants. Compare this with a sack/ shade net supported garden that has 100-150 plants. And again with conventional ground farming that has 30-60 plants over the same area. All calculations factor in the walking path
Multi-storey garden materials
- dam liner
- joining clips
- soil
- fertiliser
How to irrigate multi-storey gardens in Kenya
Pre-perforated rip lines or button drippers irrigate these crops. Frequency of irrigation is twice or thrice weekly according to the prevailing weather
Multi-storey gardens in Kenya
FAQs
1. How to prepare a multi storey garden?
As described under the heading How do you make multi-storey gardens in Kenya? above
2. What is the size of a multi-storey garden?
6 square feet
3. What are the advantages of a multi-storey garden?
- It is easy to assemble, and maintain
- It saves on land and water
- They are done over small spaces
- You can grow many typesof vegetable crops on it
4. What are the disdavantages of a multi-storey garden?
- It takes time to design and make
- It requires training to make for the first time
Shade Nets In Kenya
As the top among all shade net suppliers in Kenya, Grekkon Limited’s shade nets in Kenya are of different types and color. We have all types of shade nets for agriculture, for the production of both food, and none food crops. The cost price of a shade net roll is from Kes 12,500. Below, we answer commonly asked questions
1. What are shade nets?
They are HDPE, UV treated woven or knitted netting material that regulate the amount of light and heat from the sun, air and moisture. Shade nets reduce the temperature delta (difference between day and night temperatures), thereby avoiding a sudden temperature variation, so that plants don’t suffer from thermal shock A good degree of beneficial moisture is trapped between the ground and the net. They are water permeable so that rain water, and irrigation water will reach the crop and keep it hydrated
2. What are shade nets used for?
- In the nursery to protect seedlings from direct radiation, and harden seedlings
- In orchards and farms to protect crops from intense sunlight as well as bird and insect pests
- Shade net fencing. On a fence to block excessive wind on the crop, and to reduce the farm’s view from outside
- To cover water reservoirs or water tanks so as to reduce water loss by evaporation
- In livestock production to protect them against extreme heat
3. How much do shade nets cost in Kenya?
Tabulated below are our shade net prices in Kenya are per meters squared, by type
% Shade | Cost per M Sq In Kes |
30% | 70 |
55% | 75 |
75% | 100 |
90% | 170 |
Grekkon Limited’s shade nets are available as 50M x 4M rolls in all our branches country wide
4. What is the cost of shade net per acre?
Our shade nets for sale in Kenya by per acre are measured as 4,100M sq
% Shade | Cost per Acre In Kes |
30% | 295,200 |
55% | 352,600 |
75% | 410,000 |
90% | 697,000 |
5. What are the types of shade nets?
By material
- Woven shade nets. They are made from polypropylene, are heavier and allow heat build up. They withstand the most extreme exposure to the sun, and have minimum shrinkage. Woven shade nets are for shading of plants, pet kennels, windscreens, patios and for privacy. Woven shade nets are 30% heavier than knitted shade nets, and are difficult to install
- Knitted shade nets. They are made up lightweight polyethylene. They have an open lock-stitch design that resists wind damage, and reduces heat build up in the net. The level of shrinkage is 2% to 3%. Knitted shade nets have better longevity in agricultural use as they resist agro-chemicals and detergents. They are preferred for shade houses, and greenhouses.
Grekkon Limited’s shade nets are all knitted with monofilament fabric which is durable due to he thicker thread. A thicker thread has a longer process of photo oxidation as compared to a thinner thread, hence the longer lifespan
By % shade
- 90% shade nets are appropriate for crop nurseries located in low altitude or extremely hot locations
- 75% shade nets are preferred for nurseries in high to mid altitude locations that are also hot. They are also used in the hardening stage of seedlings in hot low altitudes. This will grow ferns, orchids and succulents
- 55% shade nets are for hardening of nursery crops, or for growing plants in very hot locations for crops that are sensitive to intense sunlight. Good for growing cabbage, geraniums, lettuce, foliage plants, cuttings, orchids and most potted plants
- 30% shade nets are for growing crops that need just a little bit of shading, yet lots of light for photosynthesis. Great for growing heat tolerant plants like tomato, pepper, roses, strawberry, cucumber and squash
By color
- Black
- Green
The color choice does not affect the performance for these two. Both allow all light wavelengths go through. However, brightly colored shade nets like white and aluminum reflect the sun’s heat creating a cooling effect
6. How do shade nets work?
They absorb or reflect the sun’s heat. They act as filters by depriving the plants of excess sunlight
Shade Nets In Kenya
How To Select The Right Shade Net
- Crop type. Some crops require more shade than others
- Stage of growth. Seedlings will be more shaded than mature crops
- Farming method. A shade net on a greenhouse will be lighter than that in the open field for the same crop
- Season. Denser nets will go with hotter seasons
- Location. Hot low altitude locations will have denser nets than higher altitude cooler places
- Usage. The wind break net, the water reservoir cover net, the greenhouse cover net, and the open field net will differ
Our shade nets are green or black in color. The color has no bearing on the net effectiveness, but is rather for aesthetic reasons. Shade nets are supported by steel, or wooden frames for shade houses
Low Cost Solar Dryers
Grekkon Limited is the largest supplier of low cost solar dryers for agricultural products in Kenya . These low cost solar dryers work on solar strength, and are also augmented with a biomass heat unit if so desired by the client. Our agricultural solar dryers design is according to the product, location, and drying volume per session. These passive or active solar dryers for fruits and vegetables are fixed or portable as the user needs it. The fixed ones are large and impractical to move about, while the portable one are small domestic drying units
What are low cost solar dryer prices in Kenya by Grekkon Limited?
We price according to size & type. The table below illustrates some sample design pricing for passive solar dryers
Solar Dryer Size | Drying Capacity | Price of Solar Dryer |
1.5m x 1.5m x 1.5m | 40-50kgs | KES 70,000 |
2m x 2m x 2m | 50-90kgs | KES 75,000 |
2m x 3m x 2m | 80-100kgs | KES 95,000 |
2m x 4m x 2m | 90-110kgs | KES 100,000 |
2m x 5m x 2m | 100-130kgs | KES 120,000 |
L X W x H |
Low Cost Solar Dryers in Kenya
Grekkon limited designs and constructs both passive/ natural circulation, and active/ forced circulation low cost solar dryers for agricultural products. The passive solar dryers have no additional mechanical input, while the active dryers do. Active solar dryers are also know as hybrid solar dryers. Their additional mechanical inputs are; a biomass heating unit, or solar powered exhaust plus extraction fans, and synchronizers. A hybrid solar dryer will have one (solar system or biomass heater) of these enhancements, or both. These enhance drying time by 30% to 100% compared to passive drying. Attached biomass heating units allow for night time drying, or on cloudy/ rainy days.
Solar Dryer Materials
- Light UV treated translucent polythene paper to allow heat and light. The paper also has anti-drip treatment to prevent dew formation which causes moulds to form on food
- Heavy UV treated geomembrane to conserve heat
- Steel bars galvanized with food-grade aluminum or zinc for food safety
- UV treated heavy gauge netting to prevent insect pests from entering
Below are 2 videos: The first one is of a farmer in Homa-bay county, western Kenya using a community passive/ natural circulation solar dryer to add value to banana produce. The second one is of a mango processor in Taita Taveta county at the county’s coast with an active/ forced circulation dryer. Both solar dryers are by Grekkon Limited.
Video 1. Video 2.
Our low cost solar dryers have shelves at different levels depending on the volume or weight of food crops to dry per session.
Low Cost Solar Dryer Design
What is the working principle of a solar dryer?
1. Passive/ Natural Circulation Food Solar Dryer
Grekkon Limited solar dryers work in the following steps;
i. Capture & collect the sun’s heat
ii. Create a ‘greenhouse effect’ which causes moisture loss from the produce
iii. Air coming into the dryer exits with this moisture from the vent
2 Active/ Forced Circulation Food Solar Dryer
In addition to what takes place in the passive solar drying unit, the fans force in hot air from outside, and force out hotter air combined with moisture from inside the dryer. At night or on cloudy/ rainy days, the biomass unit supplies the drying heat.
Pros and cons of a low cost solar dryer in Kenya
- Speed of drying. Food dries four to five times faster.
- Quality. As the sun’s UV rays do not get into direct contact with the drying food, the food’s; color, taste, scent, and nutritional value is unaffected
- Cleanliness. The food is free from dust, sand, or other external contaminants
- No pests. Insect, bird, or mammalian pests have no access to food in the dryer, so no attack occurs
- It is more expensive to build and maintain than open-air drying
Low Cost Solar Dryers
FAQs
I. What are solar dryer prices in Kenya by Grekkon Limited?
We price according to size & type. The table below illustrates some sample design pricing for passive solar dryers
II. How does a vegetable dryer work?
- Heat
They allow in diffused heat from the top and the sides, which heats up the air coming in from the air inlet. This hot air will exit with moisture in the air outlet.
- Anti-drip management
Our UV treated polythene cover has anti-drip properties so water droplets do not form on it. It prevents dripping on the drying food which is a precursor for fungal development.
III. What do a low cost solar dryers do?
Grekkon Limited’s solar dryers reduce the moisture content to less than 12% in these products;
- Plantation crops; coffee, rice, cassava
- Vegetables; tomato, onion, garlic, brassicas, hot peppers
- Cereals; sorghum, and millet
- Herbs; moringa, mint, rosemary
- Oil crops; groundnuts, sunflower, macadamia, cashew nuts
- Others; mushrooms, fish, beef, mutton
IV. How do you dry vegetables with solar?
- Wash the vegetables to remove all dirt
- Ensure there are no insect pests present
- Remove any diseased parts or produce
- Cut or grind them into smaller pieces to increase the drying surface area
Place them in the solar dryer holding trays
V. What is the most popular use of low cost solar dryers?
To dry fruits, mushrooms, vegetables, herbs, spices, coffee, cassava, banana and fish. Banana and cassava are further processed into food flour. A solar dryer ensures that the food is free of any external contamination
VI. What are the main applications of a solar dryer?
Besides vegetables and fruits, commercial solar dryers in Kenya are for fish, root crops and mushroom drying. Commonly dried foods in Kenya through our solar dryers are:
i. Banana, cassava, pumpkin, millet, and sorghum to make food flour. Dried cassava is also processed for industrial starch manufacture
ii. Moringa as a medicinal herb
iii. Tomato, capsicum, traditional vegetables, kales, and spinach as vegetable nutrients
iv. Mango, papaya, as dried fruits for snacking
v. Omena which is the silver cyprinid fish for both human consumption, and as additive to animal feed
vi. Coffee so that it’s suitable for milling. Coffee solar dryers are the largest, each holding over 5 tons of berries per drying session
Irrigation Company In Nairobi
In 2017 through 2018, Grekkon Limited was an irrigation company in Nairobi servicing small to medium scale holders. The company’s focus was on irrigation and allied services. these are;
- Irrigation. drip, overhead, and sub surface irrigation systems
- Dam liners. for irrigation water harvesting and conservation
- Greenhouses. steaal and wooden types
- Borehole drilling
- Water pumps. solar, electric, petrol and diesel types
- Solar dryers. for post harvest crop loss management
- Agricultural nets. bird nets for bird pests, shade nets for , and insect nets for insect pests
- Trays. seedling trays for seedling propagation, and hydroponic trays for hydroponic fodder production
- Coco peat. a non soil media for use in seedling trays
- Mulch paper. to manage field water loss through evaporation, weed and pest control
While improving the clients’ overall yield, and income from farming. The company focuses on this smallholder, and medium holder niche because of the presence of large irrigation service providers in the country. These companies clientele are the large ornamental, cereal and vegetable growers. Smaller growers had to fend for themselves because they were never a priority for these large corporates. A hallmark of the company is the free 4 month agronomy training programs for all their farmers. Grekkon Limited is the only company that offers this free service to farmers in Kenya
The company organizes ‘training days’ in various regions of the country. Growers come to learn of new and existing technologies.
The other objective was to do further by offering expert irrigation, greenhouse, water pumps, and dam lining expertise to these small scale to medium scale commercial farmers, who had no professional entity to consult for such. This was through physical site visits to carry out assessments, provide advice, and carry out irrigation project reviews afterwards. And so, Grekkon Limited – Irrigation Hub was born. It is headquartered in Athi River, with outlets in other key agricultural zones in Kenya
Two years after establishment, Grekkon won the coveted Most Preferred Irrigation Systems Company of the Year award in 2019. This was at the prestigious Agribusiness Excellence Awards ceremony. The farmers in their votes had finally spoken!
Irrigation Company In Nairobi
1. Irrigation Products
- Drip kits. For both vegetable and fruit tree/ forestry irrigation. This includes; drip tape, 16mm HDPE pipe, starter connectors, off-takes, drip to drip connectors, button or online drippers, and end caps
- Rain hose kits. It has; rain hose pipe, off-takes, connectors, and an end cap. Rain hose kits are best utilised where drip irrigation systems cannot be installed such as is pasture, or crop nurseries
- Sprinkler systems. There are various types;
3.1. Pop up sprinklers. These are sub-surface sprinklers for lawns, golf course, football pitches, and gardens
3.2. Rain gun sprinklers. These are metallic high pressure, high volume sprinklers for use in all crops. They are well utilised in larger acreage because they have a wide area of spray
3.3. Impact sprinklers. They are plastic and range from 1/2″ to 1″. Mostly used to irrigate small vegetable farmes, or pasture
3.4. Meganet sprinklers. These are plastic sprinklers that range from 1/2” to 1”. They are a suitable alternative to impact sprinklers
3.5. Butterfly type sprinklers. They are for lawns and small gardens like the kitchen garden
3.5. Micro sprinklers. They irrigate individual fruit tree plants, just like button drippers. However they cover a wider area, and provide better humidity around the crop’s root zone
In this video below, a smallholder farmer who was an early adapter of Grekkon’s rain hose kits. She speaks about her growing experience
4. Misters and foggers. Used in greenhouses for seedlings watering, and humidity control
5. Water pumps;
As an irrigation equipment supplier, every irrigation system is backed by the following types of water pumps to draw water from a source, to supply the irrigation system
i. Solar water pumps. These are either surface or submersible types. Submersible water pumps work under water, while surface water pumps are ground based
ii. Electric water pumps. Like solar water pumps, they’re surface and submersible options
iii. Diesel generator water pumps. They run on diesel powered engines. They are portable or fixed types. The latter are larger in size
iv. Petrol water pumps. They run on petrol powered engines, and are smaller than diesel water pumps
6. Irrigation pipes
6.1. HDPE pipes from 16mm through 280mm diameter. The pipe thickness is from PN6 through PN25
6.2. PV pipes from 20mm through 280mm diameter. The pipe thickness is from PN6 through PN25
6.3. Suction pipes for supply with water pumps
6.4. Delivery pipes as either canvass or PVC material
Irrigation Company In Nairobi
Water pump accessories
Accessories that accompany motor powered pumps are; foot valves, clips, suction pipes, adaptors, splicing kits, control boxes, invertors (for DC to AC converstion) cables, cable ties, solar panels (for solar pumps), and a solar panel support structure
Accessories that accompany motor powered pumps are; foot valves, clips, suction pipes, and adaptors
Every irrigation system has a main, and/ or sub-main pipes. We advice on the right pipe thickness, size and type based on
- Land size; determines pipe size. Large pipes for large acreage. Our pipe sizes range from 16mm to 180mm in diameter
- Irrigation system adopted; any of the 1 to 3 above
- Land ownership system; leased or owned? HDPE for the former, PVC for the latter
These pipes have specific fittings which are; elbows, tees, valve sockets, ball valves, couplings, adaptors,sockets,saddle clamps, and end caps by type and size
Irrigation Company In Nairobi
Installation Service
Our irrigation service team conducts systems installations service in east Africa. We offer advisory services to manage the system well for many years
Irrigation Company In Nairobi
Key Attributes
Innovation
Grekkon Limited in its innovation introduced the rain hose irrigation system. This new product solved many irrigation challenges for commercial vegetable and corn farmers. The company is the market leader in research and commercialization of natural solar dryers, each unit designed to meet the product or market drying requirements
Today, Grekkon Limited is the largest supplier of natural solar dryers within the east Africa community states
In 2024, Grekkon Limited introduced the first color coded drip tapes in the Kenyan market
Team
Grekkon Limited’s resounding success is largely due to its team of field professionals who provide engineering, commercial, and technical services
Country Wide Presence
As an major irrigation company in Kenya, Grekkon Limited has offices in; Athi River, Nairobi, Kisumu, Eldoret, Nyeri, and Nyahururu
Where to buy dam liners in Kenya
Where to buy dam liners in Kenya is from Grekkon Limited. The company offers the best UV-treated black high density polyethylene (HDPE) dam liners manufactured for tropical climates. Our pond liners for sale in Kenya line the walls and floors of water harvesting reservoirs. This is to prevent water loss through seepage into the soil. Changing rainfall patterns and unpredictable seasons are increasingly becoming a norm in Africa. This is why the need for agricultural water conservation is growing amongst farmers. Every farmer practicing irrigation has a water source
Where to buy dam liners in Kenya
Thickness | Weight per meter square in Kgs | Price per meter square in KES |
0.5mm | 0.46kg | KES 220 |
0.75mm | 0.88kg | KES 320 |
1mm | 0.91kg | KES 420 |
Water pans lined with dam liners are a source of irrigation water storage. This water is from a larger source such as a lake, river, or borehole water, and also harvesting rain and run-off water. Besides irrigation of your crop, the pond liners on your water pan allows for commercial or subsistence fish rearing; the former to boost household income, the latter to supplement household protein
Where to buy dam liners in Kenya
Dam liners are available in the companies 6 branches located in; Athi river, Nairobi, Kisumu, Eldoret, Nyeri and Nyahururu. We supply pond liners either as rolls of 110M x 8M, 0r cut and welded into the client’s water pan’s specifications
Where to buy dam liners in Kenya
Positioning Your Water Reservoir For Irrigation
This depends on:
i. The source of water going into the water pan. If the source is from a lower altitude water source such as a river or lake, the water pan is at an elevated position so that with a water pump, the water is reticulated through irrigation water pipes to the water pan. If the water source is from rain water falling on the roofs or run-off, the water pun is positioned at a lower gradient
ii. Preferred irrigation method. If by sprinkler irrigation or rain hose kits which require high pressure from a water pump, the water pan will be situated at any point. If by low gravity pressure say for drip or button drip irrigation, then it will be at the highest point of the farm
Where to buy dam-liners in Kenya
How to Harvest Water Using Dam Liners
Factors to consider
1. Land size
The amount of water required for half an acre is less than that needed for 20 acres. The latter will harvest more water to irrigate the greater acreage, and the former will have less water harvested. The bigger the volume of water reserved, the larger the dam liner size
2. Location
The amount of rain fall is different in every climatic zone. Growers in the cool wet highlands have just a few dry months in the year, while farmers in the dry zones have more dry months than wet. In regions where the interval between rains is long, larger reservoirs are built for the same acreage as that in the cool wet location. Again, dry locations have very high water loss through evaporation. In this case, it is advised to set up a shade net over the water reservoir to manage this water loss
3. Ground Elevation
The farm gradient determines the location of the water pan. Some choose to have it at the lowest part so as to capture run-off water. If it is for crop irrigation, this water is either pumped uphill to a tank from where it flows back by gravity to the crop. Or it is pumped directly to the crop from the water reservoir. Others choose to locate the water pan on the highest point of the farm so that the water, through gravity flows out to the crop. In this case, the farmer does not retain run-off rain water from the farm. On a flat terrain, irrigation water is physically pumped out to either a high storage tank for onward gravity flow to the crop. Or directly to the crop
4. Farming System
The size of the water pan will differ for irrigation, compared with aquaculture or livestock production
5. Crop Type
Some crops are more water demanding such as leafy vegetables, than others such as herbs. Then some crops like onion are densely spaced while others are like avocado are sparsely populated in the farm. This will determine the water requirement
6. Irrigation System
Every irrigation system has it’s own unique water use. Drip irrigation conserves water while overhead irrigation through sprinklers or rain hose kits spends huge water volumes
7. Surface Texture
The surface texture of the water pan determines the dam liner thickness to install. For a smooth surface, a 0.5mm dam liner is ok. Where the surface is stony or rocky, then the 0.75mm or 1mm dam line is better
Before harvesting your water using dam liners, ensure that the water pan’s surface is free of debris as much as is possible. This will be stones, rocks, tree stomps, or sticks. This reduces the danger of your dam liner tearing as a result of perforation caused by the weight of the water squeezing the material against these particles
Trench 0.75M to 1M along the perimeter or circumference of the water pan. This trench is 1ft wide and 2 ft deep. Your dam liner edges will be tucked in here and covered with soil, gravel or stones to anchor it in place. Alternatively, use sand bags along the edges to hold your dam liner in place
Where to buy dam liners in Kenya
How Are Dam Liner Sizes Calculated?
Before determining the dam liner size, one must understand the size of the reservoir or tank. This is by measuring the length, width, and depth/ height (for rectangular or square shaped reservoirs/ tanks). For circular or cylindrical tanks/ reservoirs, measure the diameter, and the depth/ height. The reason this is key is because our dam liner material comes in rolls. To make out the shape of the water pan or tank, the dam liner is cut in large bits from the roll and joined together. This is to create the 2 dimension size of the water reservoir or tank. For example; if the width of the dam liner on the roll is 8M, and the water pan requires a width of 15M. Then 2 pieces, one measuring 8M and another 7M in width from the roll are cut and joined to create the 15M width
How Do I Calculate How Much Dam Liner I Need?
The dam liner calculator is adapted to the shape of the irrigation water reservoir as illustated in the 3 different shapes below
- Sloped sides reservoir
The slope of the dam wall is shown as slanting length (SL) or slanting width (SW) in the dam liner calculator tabulation shown later in this page
2. Cylindrical circular tanks
3. Straight side reservoirs
Where to buy dam liners in Kenya
Pond Liner Calculator Table
Circular Liner | Sloped Sides Liner | Straight Side Liner |
(Circumference*H+0.6M) + (3.14*3.14*r+0.6M) | (SL*2+D+2M)*(SW*2+D+2M) | (L+2D+2M) * (W+2D+2M) |
If your totals include a decimal say 120.3sq, round it up to the nearest whole number, in this case 121M sq. The +0.6M in the ‘circular liner’ and is the overlap. So is the 2M in the straight side liner’
“D” is the maximum depth which is the center-most point of the reservoir
Where to buy dam liners in Kenya
How much overhang should a pond liner have?
An overhang is the extra liner material that holds the main liner in the reservoir or tank. This excess material is held against the external wall of the tank, or tucked in a trench all around the reservoir to support the dam liner in place. It is covered with soil or stones in the trench. Another alternative to trenching is to lay sand bags on it. The weight of the sand bags holds the dam liner in place
After excavation, it is necessary to compress the mould of soil roundabout the water pan before making a trench
See below
Where to buy dam liners in Kenya
How To Weld Dam Liners
- Factory welding. Depending on the dam liner size, weld it whole or partially in the factory. The weight and volume of the welded material must be easily portable on site. The latter factor guides on how much of the dam liner material will be put together in the factory
- Site or field welding. This is done on site at the point of dam liner installation. It is the joining together of the partially welded dam liner pieces from the factory. Site welding is done when the entire dam liner could not be wholly put together in the factory. This is as a result of weight or bulkiness, which limits lifting and transportation of the bulky and heavy material. The weight size of the portable material depends on the thickness of the dam liner. The thicker it is, the less it is
- A wedge welding machine or a heat gun/ heat blower is the equipment that does dam liner welding. A wedge machine is what does it in the factory. The heat gun is highly portable, and so is best for field joinery
Dam liner welding involves melting the liner material under high temperature at the point of joining them. Once melted, the 2 layers are laid one over the other and as they harden, become one unit
Both equipment run on electric power. In off grid electricity locations, Grekkon Limited provides a generator to power the heat gun or wedge welding machine
Where to buy dam liners in Kenya
A Step by step procedure on how to install dam liners
To learn how to install dam liners in your water pan or tank, consider the following factors
- Determine if;
1.1. It is a water reservoir
or
1.2 A water tank
Each storage unit has a different way of calculating the dam liner
2. Define the shape of the water pan or tank;
2.1. Is it circular/ oval or square/ rectangular?
2.2 Are the rectangular/ square sides steep or slanted?
The dam liner calculation formulae is different for each shape as illustrated later in this article
The second stage in how to install dam liners is to work out the dam liner size