A Little Help Please With Finishing Cycle

[Clair]

Hi,

After patiently waiting on my fishless cycle (using pure household ammonia) I am now nearing the end. After a week and a bit of a nitrite spike (was instantly purple on API test kit so off the scale high) it has finally dropped now to 0.25ppm, nitrates have shot up to 40 from 10 at the start of the week so thats looking good too so my question is, now that the nitrites have almost gone down to zero and the nitrates are up should I do a water change now or wait until the nitrites are at zero? Also the ammonia level is sitting at 1ppm at the moment and my lfs has not yet got the fish that I ordered in (its going to be a tiger barb only tank)so do I need to keep adding a tiny bit of ammonia in tank until the fish are in the lfs then would I drop temperature back down and change water then? When I do change water how much should I change? Sorry for it all sounding a bit confusing there are a few questions there but any advice would be much appreciated.

Thanks Clair.

 

[toshapetriji]

Wait until you get a zero reading for ammonia before adding more ammonia. Please remember you need to complete the qualifying week too.

 

[Clair]

Wait until you get a zero reading for ammonia before adding more ammonia. Please remember you need to complete the qualifying week too.

Thanks for the reply, can I just ask what is the qualifying week?

 

[toshapetriji]

when you get a zero reading for ammonia and nitrite 12 hours after adding ammonia you can consider your tank cycled. However you should continue to add the ammonia for a further week to ensure the stabilility of your bacteria colony.

This way when you add the fish you can be somewhat confident that the filter will handle the bio load created by adding the fish.

 

[drobbyb]

Agreed.

 

[waterdrop]

Yes, agree with triji, near the end of the fishless cycle it helps to become more detailed. Its finally time to try to be sure you are really up at 4 to 5ppm ammonia concentration when you add and to note the time when you add. Then, 12 hours later, you test to be sure that both ammonia and nitrite(NO2) have dropped all the way to zero ppm, no traces. Once you hit the day when that happens, you can start your qualifying week and watch it continue to perform the "12 hour double-zero drop" each day. As usual, you only ever add ammonia once in 24 hours, at your normal add time. The qualifying week helps to ensure that you won't get a mini-cycle right after doing the big water change and adding fish.

And yes, its true that you have to always continue to feed your bacteria colonies at the same 4-5ppm level day in and day out until you're ready to get fish. There's no time limit on that, the colonies will simply continue to mature if it takes more time before your fish come in. The colonies continue to mature for about a year anyway.

~~waterdrop~~