Backyard Aquaponics
A place to discuss aquaponics

I put together a simple one IBC system with approx 650L FT and 300L GB about 8 weeks ago. Added humonia to start and 5 goldfish about a week in with another 10 added a couple weeks after. After about 3-4 weeks the ammonia levels dropped and have stayed low since then, however, the nitrites have remained high since then. The fish seem to be happy enough. Algae is growing on the sides of the tank. Plants in the GB are growing but some have yellowed leaves which I am not sure whether this is due to lack of nitrates or Iron. I have added some Iron chelate today.

I know system cycling is all about patience but mine is running out. The water temperature has dropped to an average around 15C at the moment.

Is there anything I should be doing or is more patience the key here?

what are the actual readings?

If your ammonia is 0 you shouldn't have high nitrites for longer than a week or 2... Maybe do small water changes to bring your nitrites to around 2-3ppm and then let it finish up on its own.

High nitrites will kill your fish over time... they tend to live for quite a while then kick the bucket.

Thanks tcshad,

Hard to know exactly what the actual readings are as the test only registers >3.3 mg/L but I suspect they are much higher than this as diluted tests have produced the same colour change. See attached image for more detailed testing etc.

How much aeration do you have?

The only aeration I have is from the draining of the GB and the constant return of the excess pump water.

Not enough DO for happy bacteria???

Adding more aeration will often kick the nitrite spike over....

Are you running timed.. or continuous siphoned??

Have a bell siphon. Cycles roughly every 15 minutes.

Finally cycled!

Drained a bit of water to increase aeration from the venturi which was partially submerged and added a little more Iron Chelate. Probably none of this made any difference but in any case nitrites have dropped and nitrate is up.

The increased aeration probably helped...

I'm not a 100% sure... if that's 100% wrong... or 100% right....

Whoa I didn't know that. Useful info! Cheers..