One of the challenges in having longer term plants, that lives more than 4-6 months, in aquaponic growbed is that they fill up the grow media with roots over time and it increases water level in the growbed. Also removing older plants from the growbed becomes very hard.
A new experiment is in progress to reduce the intensity of this problem. I am removing media (gravel) from a growbed so the growbed will have just water in it, and then to place pots filled with grow media in the water. It will look like a vegetable plant in a pot but the pot itself is placed in water with top two inches above water. I am using pots with holes around it for easy waterflow and for roots to extend into water. This way we can easily lift each pot/plant out of water or move around in the growbed.
Technically, this is a hybrid of deep water culture system and media based system. Hybrid has the advantages of deep waterculture that it is easy to maintain plants and doesn’t need as much grow media. Also it has the advantages of media based system that plants get good footing in the pot, media in the pot provides space for nitrification bacteria to grow and water filtering happens through the grow media in the pot by letting water from fish tank flow straight into the pots.
Will keep you updated on the results.