I just got a new aquaponic system setup today. 🙂
We have a 5 ft tall metallic stand on our roof top for keeping a back-up water tank for our home water supply. I utilized the bottom of this stand for setting up a fish tank. Metallic sheets of about two feet height were welded between the four legs. Then used a polyethylene sheet as the lining. This should hold about 500 litres of water.
Added two growbeds to the system. One is a small new growbed made from a used blue barrel. Second one is a reuse of a similar sized old growbed that was connected to another system earlier. These together would give only about 6-7 sq ft of grow space, which is about two thirds of the capacity what this fish tank can support. I will need to add one more growbed of similar size soon.
Growbeds are kept very close to the fish tank so that plumbing for getting water to the growbeds is easy.
This system will keep constant water level in the fish tank and for now I am keeping the growbeds in constant flood mode, meaning growbeds will always have water two inches below the surface. I have kept a 2000L/hr (30W) pump in a common sump tank for pumping water back into the fish tank.
I temporarily stopped an existing small system for maintenance 🙂 and moved 10 or 12 tilapia into the new tank. Fish are looking happy. 🙂
I plan to plant long beans, cucumber and may be a melon plant (experiment) on these grow beds.
I’ll keep the system running for a couple of days before planting, just to make sure everything is running fine. Will keep the progress posted. 🙂
Finally it’s happening! I have been wanting to clean up the media in one of my older growbeds and convert it from constant flood into a flood and drain system. Also wanted to take my hybrid experiment to the next level.
I got external help for cleaning the grow media as it is a labour intensive activity (yah, I am lazy 🙂 )
I had him clean the gravel and leave it outside of the growbed for the time being.
The plastic inside growbed tank (it’s an IBC) is already starting to break so I have put in a polyethylene lining inside the tank, so that hopefully I won’t have to worry about this system for at least another year.
We are running short of water supply over the last couple of days so I have kept the bed in half done state but in shape to keep the water filtered for the fish.
I have a couple of containers getting ready for planting.
I hope to get this system fully functional over the weekend. More coming.
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.
Plant in the gravel filled pot
Plant in the gravel filled pot
Last week I was travelling and, as if our aquaponics system knows when I am out of station, a growbed became flooded and gave my wife a hard time. I got back home over the weekend and we did some investigation. It turns out that the growbed is full of roots to the extent that water won’t flow through the grow media anymore.
One of the advantages of aquaponics is that we don’t have to get our hands dirty working with soil (yes, I can hear you, I agree, I am a lazy farmer 🙂 ), but having to clean 12 cubic feet of grow media tangled in roots isn’t fun either!
I seriously think I need to switch to deep water culture instead of media based growbed. In deep water culture, plants are suspended or stays afloat on water surface and roots hang into the water. This way taking a plant out is very easy. It has its own set of challenges, but I think that’s the way to go. Actually, most of the commercial aquaponic systems use this method for growing plants.
Sounds like a busy weekend is ahead! More on deep water culture coming.
Growbed is filled with roots
Water is getting filled above media
I have a newer smaller system that I have kept for cycling (to have the nitrification bacteria population established). It looks like the system is doing well now.
I have bottle gourd (churakka), long beans (payar) and amara payar (not sure of the English name – hyacinth beans / gour beans?) planted in it – just one plant each. Bottle gourd plant has a couple of small bottle gourds on it already. Will post how well it does.
Bottle gourd in constant flood