Trying out aquaponics.

Aquaponics is something I have wanted to try for a long time. I have used watercress indoors growing in trickle-filters and in the stream on my pond, but would like to try to grow other plants using this method. It is also a practical idea because I have an overstocked aquarium (not my own doing, Guppies and cherry shrimp never stop breeding) and a pond full of fish. This means there is a lot of nutrient rich water available.

As a test with a look at making something larger for outside in the spring, I decide to make something small to fit on the top of my aquarium. I wanted something I could slot my existing 10cm self-watering pots into except instead of using pint glass reservoirs they would get aquarium water in a constant flow.

I started by buying a plastic trough tall enough to accommodate my 10cm pot, a gap and then enough of a reservoir to work. I then made polystyrene top out of a poly-box lid. this added another 2cm to the pot heights. I drew round the top of top of the pot and cut inside the line, to make three holes big enough to fit the pots but small enough for them to not fall through.

Lid with wholes cut and one plant installed

I used a drill to make a 22mm whole in the bottom of the trough. I bought a 22mm overflow plastic bulkhead fitting. I use this size because they are cheap being the standard fitting used on overflows on water tanks. the fitting stood just tall enough inside to leave quite a lot of room for water roots. it also had a cap that made it slightly taller. If I wanted to though I could always add always add a riser to make the reservoir deeper, as long as I leave some space above and don't dip the pot in the water.

Bulkhead drain

I made another whole in the side of the trough to act as both an entry point into the trough for the inlet pipe and air pipes, but also as an overflow if the bottom drain became blocked.

Inlet entry/overflow

I used a small aquarium filter (because i have many around the place) and a piece of tubing to pump water up into the trough.

 Once it fills the trough to the level of the top of the bulkhead fitting it overflows back into the aquarium. I added a couple of air stones on an air-pump because I had one spare and new it would help get oxygen around the plants roots.

Final view inside trough, showing air-stones, inlet and bulkhead outflow.

I Once all put together I have installed three of my Capsicum baccatum as they are two big for the grow areas and don't like the cold in the windows. I also picked plants that already had roots long enough to reach the water in the trough, also their wicks just reach the water. I have got a small light on there at the moment and they are near a window but I may swap some lights around and see if I can give them a bit more.

Whole tank with aquaponic trough installed

 (although I don't know where all the fish were hiding during this, there is masses in there).

I really look forward to seeing how the plants do in there and if they have any impact on nitrate/phosphate levels in the aquarium. if they do well, I will consider making a much longer version for the side of the pond in the spring.

Happy growing!