Backyard Aquaponics
A place to discuss aquaponics

Hey all, I set up a Barrelponics system late last year to learn about Aquaponics. Thanks to Travis Hughey for making his solid, clever design available. I'm sure most people here know the setup well, but in any case "system.jpg" is a pic of mine.

You'll notice there's no top tank. I'm putting this off until I can find a good substitute for crayfish / yabbies or shrimp. Unfortunately crustaceans are banned in South Africa, something about them driving native fish extinct if they get into the waterways.

The system's been stocked with fish (5 goldfish and 20 tilapia, all about index-finger size) and plants (mint, peppadew, parsley, rosemary, basil, stevia, thyme) for about 3 months, though some of those plants were added recently. I've introduced a few other plants as seeds or seedlings in Rockwool cubes, but so far only parsley and basil have been successful. A tomato seedling is technically alive, but doing its best Bonsai impression.

The water in the fish tank has a pH of 7.8 and an EC of 0.3, our tapwater is ~8.4 and 0.2. It seems the pH should be lower - even considering I topped up the tank with tapwater before measuring - and the EC higher to support this number of maturing plants...

The mint and stevia are thriving, and the thyme, basil and parsely are sustaining - I'd like to see better growth from them. One sprig of the rosemary is dying at the tip, and all the peppadews are doing badly. Their leaves yellow, develop holes and drop off except around the top of the plant. I've included a pic of these leaves as "peppadew.jpg" and "peppadew2.jpg"

Now, I figure the problem here is nitrogen deficiency. Yellowing and brown spots that become holes, and leaves softening then falling off seem like the classic symptoms. I'm going to get another 25 tilapia soon, hopefully their "efforts" will solve the problem!

I aim to build a bigger capacity IBC system once I've got this one running smoothly, so I'd appreciate advice on achieving that, or any other comments from you guys.

Always good to see another Barrel ponics system...

What sort of feed are you using, is it a quality feed?

It's a dry pellet feed I got at the pet shop, I think it's decent. I'll upload a pic I have knocking about.

I got another 53 fish, for a total of 78. They were from the same tank / generation at the fish-farm as the initial 20 I put in a few months ago, but on average the new ones are 2 - 3 cm. smaller than my old ones. The fish-farm operator said the size difference is due to mine not having to fight for their food. It's possible higher quality feed is also a factor. The guy also said he likes a lot of algae in his tank, he thinks it neutralises fish toxins. Anyone know if complimentary bacteria in the water itself will convert fish-wastes for use by algae? Or if certain algae can take up the wastes directly?

Anyway, watching the plants in the beds to see if they'll perk up. Building a pond in case the Barrelponics gets overstocked. I might add koi to the pond if I can find cheap ones. Will similar-sized koi and tilapia get on? I don't want a bloodbath on my hands.

I'd also like to know if anyone's got a simple and pleasing design for an aquaponics pond? Would be nice to have good plants round the edges. I'm thinking of some sort of media-filled, ebb & flow moat around the pond which gets filled by the pond fountain (somehow) then drains by siphon, but maybe there's a better way.

Way to go!! I am just now in the airport returning from a trip to HongKong where I have built the second system in mainland China as a training tool at a school there. Keep up the great work. The design is proving to be very adaptable using local materials.

Travis

Any chance of a couple of photos Travis? Sounds great!

China huh? That's cool. Aren't they the ones that started all this business by keeping fish and eels in their rice paddies? You'd think they'd be ahead of the curve.

Anyway, the EC has gone up to 0.4, I reckon from the addition of the new fish. I brought the pH down from 7.8 to ~7.2 with pool acid. The plants seem to prefer this richer and more acidic water, I'm seeing less yellowing and leaf-loss from the peppadews.

I added to the grow beds some basil and lettuce from the nursery, and put similar lettuce into a raised compost bed at the same time. Will be interesting to compare aquaponic lettuce to fertiliser lettuce.

As I have an interest in biodiesel, I scraped what I assumed to be algae from the sides of the flush tank, to test it for oil content. But... I made a curious discovery! I have weird red worms in the flush tank. I've uploaded a pic, I found them in the dried "algae" while pressing it. They're about 5 mm. in length and a translucent reddish-orange colour, still wriggling when photo'ed.

If someone could help me identify these worms, that'd be good. I doubt it, but there's a chance they're fish parasites. Or maybe beneficial worms from the grow beds? Or algae-eaters / decomposers that feed on slime?

Also, is the algae I harvested really fish poop? Bit of an odd question I guess, but it squished right through the garlic press like soft paste, which isn't what I expected. Either way, doesn't look like I'll be fish-fueling my car any time soon.

Looks like mosquito larvae

Thanks Francois. Mosquitos eh? I've tussled with their kind before. Surprised they go for such aerated, agitated water.

Thought of putting tilapia in the flush tank to eat them; the tank doesn't empty completely of water due to indented bungs. I could mesh the drain to stop the fish going down the pipes and into the grow beds. Problem is the valve could still come down to mash them.