Yesterday, Lora K. from Island Leafy Greens suggested that we fill the bottom of our net pots with Hydroton and then place a small amount of Sure To Grow (STG) Loose Fill on top. Since the Hydroton can be reused many times and the STG can only be used once, this combination will save money every time we germinate seeds as compared to using only STG.
Lora’s suggestion led me to ask: What is the most effective growing medium or combination of media in an aquaponics deep water culture (DWC) raft system? Which medium is the most economical? Which is the easiest and most efficient one to work with? Which one results in the healthiest, fastest growing, and most productive plants, vegetables, and fruits?
To begin our search for answers, we removed some of the STG fill from the net pots that we filled yesterday and then added Hydroton to the top 1″ of each of the pots. This was close to Lora’s suggestion, except the Hydroton was on top instead of the bottom. Since the STG is made of a wicking material, it should pull the water up to the seed and the Hydroton should provide stability for the plant and plenty of oxygen around its base.
Here are some of our net pots with the STG loose fill in the bottom and Hydroton in the top.
During the next month or so, we will test a variety of other growing media that have been recommended:
- Hydroton in the bottom and STG on top (Lora’s suggestion)
- STG Loose Fill
- STG 1.5″ cubes
- STG Hail
- Coconut Fiber (coir) and Vermiculite
Initially, the Hydroton seems to be the most economical option, because it is the only one that is reusable; however, the STG 1.5″ cubes would most likely be the easiest and quickest to use. This makes a lot of sense to us, but we don’t like to guess. So, let’s find out…