Backyard Aquaponics
A place to discuss aquaponics

Ok so someone gave us a free small fish tank when we bought a 2nd hand fish tank off gumtree as a quarantine tank.

Now that the big Aquaponics system is cycled and has fish in it, I would like to set up this tiny tank as a small indoor system for the kids and because it doesn't make sense to be doing a water change every 2 weeks when it could be self -cleaning.

It takes approx 16 liters and has one 2inch gold fish but I'm thinking of getting 2 more so the 3 kids have a fish each.

I just bought a cheap Tupperware to act as the growbed, which will take about 6Litres before media. I have a small water pump so now I just need to figure out plumbing and which plants would be appropriate.



So my main questions are about stocking density (Can this growbed support 3 goldfish?) and what plants can I grow here.

I'd like to plant something fun for the kids. Could we grow strawberries? Or does it need to be shade-loving like impatiens or peace lillies?

Depends on the lighting. I would think that your GB would support the fish, it's just a matter of monitoring your chemistry and regulating feeding accordingly. As you're certainly aware, kids are apt to overfeed since feeding is how children love fish so having a close eye on is important. I'd start with something robust like spider plants, peace lilies, baby's tears and the like for starters: success right out of the gate helps build confidence and once you have the system established can experiment with additional varieties.

Some progress:




I tested the water this morning and Ammonia was down to 0.25ppm from 1ppm and Nitrates were 1ppm and Nitrates were around 10ppm.

Growbed is now filled with scoria and pump is running F&D on a 30 minutes on and 30 minutes off timer.

I'll take more photos once I plant it up.

Problem: pump is not running any more... Just making loud clicking noises...

I have decided to ditch the el cheapo water pump for this small system by eventually building an airlift water pump.

This is a great diagram that basically demonstrates how an airlift pump works:



It should also be able to handle lifting some fish poo from the bottom of the tank and dump it into the growbed.

I've bought a cheap air powered filter off eBay that works on the same principle and I'll just extend the outlet pipe so air and water come up into the growbed. I'll try first with a curved pipe that comes over the side of the growbed - but if that doesn't work I may need to drill another hole for a vertical water delivery pipe into the growbed. Much like the standpipe but a bit higher so water doesn't drain down it when the air pump is off.



Hopefully the air pump will be less phased by being on a timer 24/7

to avoid big water level fluctuations in such a small tank run it as constant flood.
(ie. water always in GB container, doesn't matter if you run pump all time, but may as well)

when you want to do a water change you can siphon (with a piece of hose) from either GB or FT.

also be a bit careful with the tupperware GB propped like it is. May be best to put something under it across the tank. Will be a bit more weight when you add media.

I've been running it as constant flood since the pump tried to die on me.

Because the system is so small though I worry about water just running across the top and anaerobic zones forming... I'll reduce the pump speed to its lowest today and see if that makes a good difference.

There's a small hole drilled in the bottom of the standpipe so maybe if the pump is slower the flow of water through the hole and the top of the standpipe will even out.

I do plan to build a frame to support the growbed - but for now the aquarium seems to be coping ok with the weight.

Feeling pretty chuffed!

I upgraded my daughters' tank to 20L and stocked it with Neon Tetras.

Found a white tub to act as the growbed and set myself the task of building a stand for the growbed from Merbau offcuts.

I still have to glue and sand all the joints and probably paint the stand white too - but I'm pretty happy with how sturdy and neat my stand is!