Spaqaponics

[Dazlar]

My house came with a spa which doesn't get used much so I decided to convert it into an aquaponic system. I mean why not, the tank and pump are all there, the fence keeps the dogs out. All I had to do was put a 40mm T piece in and then run a 4 way hose connector up to the first pipe. The four way allows for future expansion and flow control. The 90m down pipe with holes and clay ball trough is all pretty self explanatory.



I initially had a hose run off back into the spa but this was not enough to cope with the throughput so I added more pipe



I then laid out my seeds in a rockwool grow tray, which I water with seasol, and let my inner geek create a spreadsheet of it (the little flag is A1)


Our first visitors are 10 redclaw we pulled out of Pine dam at the weekend.

[Threefiftyseven]

great idea and setup dude!

[benwalters]

Good idea Dazlar,
you could then let unwelcome guests take a spa and perhaps they could contribute some nutrients as well,
cheers
BW

[ZooRod]

Good idea. I assume that you will be adding fish to the spa or will your spa be the sump and you'll add another tank for fish?

[Dazlar]

Haha extra nutrients, interesting thought, maybe I should add a small shark to keep them out.

I have kept the spa hacking to a minimum with the aim that it can be turned back into a spa at a later date, you never know what the future holds.

I got a lot of the downpipe from a mates guttering upgrade. All up, with multiple Bunnings trips, seeds and hdroponic miscellania (rock wool, seasol, lettuce pots, hydroton) it has cost about $200.

Yes, I will be adding fish later, I wanted to get the system going first and I have redclaw on tap so I will just stick with them and the seasol for a bit till I have got it settled.

From what I've read, 50 jade perch would go well in there. As we are heading towards the colder months I may hold off until next year. Hopefully they will grow nice and strong with the jets to play in.

This system doesn't have a sump which could be an issue. It is all a bit experimental, a delicious work in progress, lot of fun and bringing daily smiles.

[MrWright]

From what I've read, 50 jade perch would go well in there.

Are you basing this off how many litres (of water) are in the spa or by the capacity of your media grow beds (assuming you will be using media grow beds)?

[davidl]

Dazlar,
The number of fish/red claw you can keep is dependant on the filter capacity, not the tank size. Filtration is done by bacteria growing on surfaces. You have very little surface area with the spa and NFT channel. Most plants do not absorb ammonia directly, they rely on the bacteria that grows on surfaces.

Providing lots of surface area is what the gravel, hydroton, or expanded clay beads is for. The fact plants hang on to gravel for support is irrelevant for the water chemistry. I think you need a lot more surface area, aka gravel.

For 50 Jade Perch I'd advise at least 500L of gravel, hydroton, or expanded clay beads. Though with your using NFT as well you may get away with a bit less, but not that much.

[Dazlar]

Wow, thanks David, looks like I will have to revise the battle plan somewhat.



I currently have 35 lettuce pots in the zigzag, that contains the rockwool and some hydroton. The trough, is full of hydroton, but even so, that is still only about 20l... which leaves me about 480 short!!



I have another 3m fence that I was going to do the zigzag again if all worked well. I was going to put the pots in but it sounds like I need to fill them with hydroton. That would probably bring me up near the 100l. I am guessing I would get 20 fish in there with 10 redclaw???

Maybe put an ebb and flow bed in near the return?

[davidl]

I forgot to mention, that the bacteria also need oxygen in the water, so a long constantly flooded trough will not pull in as much air as a flood and drain system. It may also run out of air part way down the trough, and you'll have the wrong type of bacteria grow there. Probably some form of anaerobic bacteria.

I'm guessing the flood and drain works well because the thin film of water on the gravel has a large water/air interface surface area as the system drains. The flood and drain action pumps the air in and out of the gravel, sort of like lungs.

[davidl]

ps. If you like the NFT style for the actual plant growth, I think it'd be fine to have a 1000L IBC tote tank full of gravel/filter material/expanded clay/hydroton doing a flood and drain thing, with all the plants in NFT channels.

Though 1000L is a fairly large amount to be flooding and draining simultaneously.