Backyard Aquaponics
A place to discuss aquaponics

I am setting up my first aquaponic system and am wondering if it is possible (or advisable) to run without any type of powered aeration? Is a venturi, U-tube or any other such measure sufficient to aerate my system. My system will be a basic IBC cut in half to form the tank and grow bed.

Also has anyone got any tips for which water pump to buy?

Cheers,

Yes it's possible.. as long as you keep your stocking levels within reason...

But it's only good... as long as the pump/electricity is on....

So, no.. it's not advisable to run with passive aeration only IMO... you should have at least some sort of battery backup aeration as well..

I am not running any bubblers, all my aeration comes from gravity fed drainage pipes from 4 bathtub growbeds. Fishtank is 1000l ibc with 28 silver perch growing for 21 months. No sump tank

No 6 hour electricity failures either?

Nope, most was a couple of hours and i have a battery pack and 12v bubbler on standby

I currently don't have an air pump and had a power outage for nearly 3 hours the other evening.

I only have 25 koi in a 5000 litre fish tank but.

If I had Trout I would definitely have an air pump.

How about Oxygenator plants for adding O2 without the need for electricity? the ultimate in passive aeration! We have 2 baths with about half a dozen goldfish each, and an end of each has what I think is Parrots feather (Myriophyllum aquaticum), which is an invasive water weed, but easy to pull out if it gets too thick. It comes and goes in the baths here, and hasn't crowded out the other water plants. There are quite a few other useful species of Oxygenators- I think many plants with underwater leaves and thin walls will do a reasonable job.

Wouldn't that leave you a problem if the power went out at night?

I think the only problem with aquatic O2 producing plants in the system is that means you have direct sun light into the system and hence are going to algae problems if you have anything near respectable nitrogen levels. Algae has a way of stopping everything up and when it dies off it robs your system of O2 hence killing off your fish and throwing the entire system out of balance, if any of the more experienced members here can refute that please do but that is the way I understand it.

Maybe position the Oxygenator plants under a small exposed area- the rest can be covered, and they do consume nitrates themselves. The water in our 2 baths, which are in full sunlight, is clear- algae does grow on the walls, and that is what the goldfish eat- we dont feed them at all.

Yes.. plants will produce oxygen during the day... but they'll consume oxygen during the night....

Indeed, but if they are growing, then surely there would be a net increase in DO levels over time... up to DO equilibrium?

Aquaponics is an oxygen intensive system, it is consumed throughout the entire system by fish, worms, and bacteria. If aerating the entire system were as simple as growing some aquatic weeds life would be so very simple, but the volume of O2 consumed is quite a but more then you would imagine. Think about it, lakes and ponds with heavy weed growth can still be O2 deficient even in full sun light and their stocking density is nowhere near what an AP fish tank is. Not saying that aquatic plants would not increase O2 levels slightly but the tradeoffs seem to make it not worth while in my book. You can have complications with algae blockage, REDUCED O2 leavels due to plant die off and at night, not to mention the reduced nitrate levels because those aquatic plants need food too. I think I'll keep my fish tank shaded

No air pump, just a bell syphon. Only 15 SP in a single IBC GB/FT setup. Tank lept shaded in summer to keep temp down. Not over stocked, not over feeding. Expect to eat my fish next year (@3years old). Cheap pump from Bunnings 1300l/hr ish. probably aqua one or something I think. max head 600mm when water level low.