My First POC after 19 days |
Using the Kratky method requires:
- A container
- Water
- Water soluble fertilizer
- A way to suspend and anchor the plant
- A plant with roots
Building
The container can be upcycled material. I have used: liter soda bottle, ice cream buckets, and other gallon food buckets. The container needs to be waterproof (plastic is easiest), food grade and stop light from getting the roots. Spray paint translucent containers to prevent algae growth. Water should be the PH of plant requires. Fertilizing solutions and recipes for specific plants can be found at any hydroponics store. Net pots or hole-punched solo cups are a cheap and easy way to hold the plant. To keep the plant from sinking and to cover the roots use: perlite, vermiculite, or coco coir. To suspend your net pot or cup you can use a lid or styrofoam (make sure that the styrofoam is held by the edge of the container). I use rock wool to seed plants. A tray of vermiculite can be used to seed as well. Once the plants have roots you can add them to your Kratky container, with the fertilizer solution covering the half the plants' roots.
Fertilizer
Remember to use water soluble fertilizer. Do not use fertilizers that depend on bacteria to be broken down. Fertilizers that are meant for soil, such as Miracle Grow, will contain nitrogen that will not be utilized. A good rule of thumb is to use fertilizer marked for hydroponic, ebb and flow, or NTF systems.
There is an order to mixing fertilizers. Epsom salts and base fertilizer can be mixed in separately first. Mix the solutions or powdered fertilizer components, until, the solution is homogeneous. Nitrogen and then Calcium should be the last thing that you mix into your solution. Several theories have been explained to me. I remain unsure, but the best explanation was that the nitrogen and calcium need other chemicals to bind to or they evaporate or sink. This is called “fall out”. If nitrogen or calcium fall out of a fertilizer solution, plants will be stunted.
My Experience with Fertilizer
Most suppliers require a premium or a large purchase. I use industrial fertilizers from Hydro - Gardens. I can order smaller amounts of fertilizer. They are the least expensive with the best results, in my experience. Hydro - Gardens website is . . . awful. I use their catalog. Daniel calls them to place his orders, as he does not plan as far ahead. I buy my Epsom salts from the grocery store, as it is cheaper and the same chemically.
Pocket Scale |
Recipes are Guidelines
I use Hydor-Gardens suggested recipes (found in their catalog) with only small variations. In Arizona, there was a lot of calcium in the water. I reduced the calcium in the recipe. In Wyoming, I do not need to add as much nitrogen. The PH is 7 in Wyoming. In Arizona, it was 5. I did not have to adjust the PH is Arizona, because once I added the fertilizer I was at a perfect PH.
Observing your plants will tell you how you need to adjust your recipe. You will likely still get growth, but your plants could do better with the best fertilizer recipe. For example, if your plants are vivid green you may need to cut down on nitrogen. If the leaves are curling you may not have enough calcium.
MPH Gardners Float Table Video |
Bernard A Kratky rediscovered this method. I say rediscovered because it is speculated, The Hanging Gardens of Babylon, used this method. Mr. Kratky found that plants have roots that need oxygen. With an air gap providing oxygen, plants grow faster. Without all the downfalls of soil gardening plants are able to grow faster. Basically, the plant pulls the needed nutrients and oxygen without interference
What to Plant
Lettuce is the best crop for a Kratky Float Table. Other short-term green plants with low nutrient draw are good choices too. For example: Batchoy, celery, and Chinese cabbage. If you prefer to harvest young mint and basil the Kratky method will work too.
I jump-start my dutch bucket plants using the Kratky method. However, dutch bucket plants are flowering, fruiting plants. For example: cucumbers, tomatoes, peppers, and squashes. Fruiting plants nutrient demands change as the plant flowers and fruits. A dutch bucket system has a reservoir that’s fertilizer solution is changed for each stage of the plant's development.
What Not to Plant
Do not plant tubers. Do not plant, plants with rhizome. Do not grow plants with long growing seasons and high nutrient draws.