The term Hydroponics originates from Greek words “Hydros” – meaning water and “Ponos”- meaning work. Hydroponics is a technique of growing plants without soil by using mineral nutrients dissolved in water to feed the plants. Hydroponics growing saves a lot of water and is ideal for desert-like places where water is very scarce. Terrestrial plants such as small herbs and vegetables can be grown directly with only their roots exposed to the nutrient solution. But some plants may require growing medium such as Rockwool, Coconut fibre, Sawdust etc. This innovative technology to yield more crops from a smaller growing area is now gaining popularity among farmers in many countries.
How does Hydroponics system work?
There are many types of hydroponics systems such as Static solution culture, Continous flow culture etc. Of all Nutrient Film Technique (NFT) is the most popular hydroponics system used. Nutrient film technique is widely used hydroponics system that combines benefits of all other systems. NFT enables farmers to achieve higher production and superior quality produce.
NFT Hydroponics system
Nutrient film technique is a Continous Flow hydroponics system where nutrient continuously flows down in small water-proof PVC channels over plant roots. There are three main components of Nutrient film technique- NFT channels, Reservoir, Growing medium
NFT channels: NFT channel is the most important component of the technique. Majority of beginners use small PVC pipes as NFT channels which are easily available. But PVC pipes are not recommended as nutrients are unevenly absorbed by plant roots because of their circular profile. Therefore it is advisable to use NFT channel of a flat profile and sufficient width.
The slope of NFT channel is also an important aspect that most of the beginners fail to check. When the length of NFT channels is greater than 10 feet, it is highly recommended to maintain a minimum slope of 1 in 75 for NFT channels. A Proper slope of the channel ensures that there is no blank nutrient spot along the NFT channel and Nutrient solution flow is uniform throughout the NFT channel.
Nutrients Reservoir: Various types of reservoir tanks made of Food grade plastics, Earthen crocks, Pinewood tanks etc. are utilized in a hydroponics system. Nutrient Reservoir tank consists of nutrient solution mixed with water in required concentration. Nutrient solutions are composed of a blend of various minerals such as potassium, calcium, magnesium, nitrogen etc.
The nutrient reservoir has an automatic water pump attached inside the tank to pump up the nutrient solutions to NFT channels. During daytime, plants require oxygen to grow, so as to oxygenate the solution in nutrient reservoir an airstone attached to air pump is submerged in the reservoir.
Growing Medium: Growing medium is used to support plants and to hold nutrient solutions around the roots. There are many types of growing medium such Clay aggregates, Sand, Gravels, Rockwool etc. Rockwool is most widely used growing medium as it is easily available and is very effective.
What are the advantages and disadvantages of hydroponics?
Hydroponics offers numerous advantages over traditional farming. Hydroponics systems require only 10 % of the water that traditional agriculture requires. Hydroponics is widely used in countries such as Isreal where there is lack of fertile land and water. However, there are many additional advantages of the hydroponics system.
- 90% saving in water used by plants
- Unconsumed nutrient solution can be recycled
- No requirements for pesticides
- Saving of high labour cost by automatic watering and fertilizing
- Clean Organic produce which is directly ready for market
- All year round growing cycles
- No environmental pollution due to harmful pesticides.
Apart from above-mentioned advantages, There are several disadvantages associated with the hydroponics system.
- High initial infrastructure cost
- Power outrage causes pump to stop working and can ruin crops
How to build DIY homemade Hydroponics system?
Hydroponics is the really simple technique to grow small veggies and herbs at home. DIY Hydroponic is cost-effective as they use the least amount of resources and are very easy to set up. There are many complex hydroponic systems being practised by professionals but the problem is that they require a lot of equipment such as pumps, channels, air stone etc. and above all, any failure in power supply can almost completely ruin your crops. So we are going to discuss a very simple DIY hydroponics system popularly known as the Kratky Hydroponics system which requires no pumps, no channels, no electricity and above all IT IS SUPER CHEAP.
- 2 Seedlings
- One 5 gallon food grade Bucket
- 2 Net pots (depending upon your plant size)
- 2 Rockwool Cubes
- Hydroponics Nutrients.
Kratky Hydroponic system
The Kratky method is a simplified non-circulating Hydroponic system. It requires no pumps, no channels, and no electricity. It has very simple set-up and is almost maintenance free. The Kratky method is more suitable for leafy green vegetables such as Lettuce, Kale, Spinach etc. Let us now discuss how Kratky hydroponic system works
Now, take one empty 5-gallon food grade bucket. With the help of a drill, make two uniformly distributed 3-inch circular holes on the lid of the bucket.
Place 3-inch net pots inside the holes and make sure that the net pots get properly adjusted in the holes. Then, take two seedlings ( which are pre-grown in soil) and place it inside two Rockwool cubes. Place the cubes inside the net pots.
Before closing the lid, fill the bucket with hydroponics nutrients up to the half the level of the bottom of net pots(see in the figure), so that some of the roots which are submerged into nutrient solution can easily absorb nutrients whereas other roots which are exposed to air can absorb oxygen.
Now place the whole assembly in a closed outdoor place which doesn’t receive direct sunlight.
Precautions of Kratky Method
While the Kratky method may seem super easy for beginners, there are many precautions that should be taken care.
First, the water used for preparing nutrient solution should be strictly filtered. If normal tap water is used, the nutrient solution would possess a very high concentration of salts in it which would increase the ppm of nutrient solution.
The bucket should be placed in a clean indoor place which doesn’t receive direct sunlight. If the bucket is placed in outdoor place which receives direct sunlight, then algae and other pests may grow in the nutrient solution.
While preparing the nutrient solution for the first time, many beginners make mistake by adding more nutrients to the water. This is a big NO, as it would increase the pH of the solution and would alter the growth of seedlings.
If you are planning to grow large plants such as Tomatoes, Okra etc. then you have to increase bucket size to 10 Gallons, and extra support should be provided so that the growth of the plants remain smooth.
If you are growing vegetables or plants for the first time then it is advisable to keep a check on the pH of the solution every four-five days. pH metres are easily available in nearby science store, or you can go for ‘use and throw pH strips’ which is comparatively cheap. You can easily adjust pH of your nutrient reservoir either by adding more water or by adding more nutrients
One more mistake that beginners make while using Kratky method is directly planting seeds in Rockwool cubes, and placing it in net pots. Only properly grown seedlings about the size of two to three inches should be placed in Rockwool cubes and then suspended into net pots.
Featured Image: https://commons.wikimedia.org/wiki/File:CDC_South_Aquaponics_Raft_Tank_1_2010-07-17.jpg
Nutrient film technique: https://www.nasa.gov/vision/earth/livingthings/biofarming.html,
Kratky hydroponic system: https://www.ctahr.hawaii.edu/hawaii/downloads/three_non-circulating_hydroponic_methods_for_growing_lettuce.pdf