fishless cycle

[FastFish]

So it's about week 4 or 5, and my 55g is at the point where it can process about 2ppm NH3/day. I'd been worrying about how the nitrite-eating bacteria are doing, since my nitrites were up at 50ppm+. So I decided to do a huge water change, to bring nitrites down to where I could control that aspect of the cycle. I didn't do a 100% change in case that should disrupt the bacteria in the gravel or something, I did I think 4 consecutive 60% changes, and nitrites were diluted to about 1ppm.

Yesterday:
NH3: 5ppm
NO2: 1ppm

Today, at the same time:
NH3: 3ppm
NO2: 3ppm (within limits of precision)

Since an ammonia decrease of 2ppm should correspond with a nitrite increase of 5.5pm, I'm inferring that 3.5ppm of nitrites were processed within 24hours. So now I'm unsure exactly what I should be doing, do I continue to maintain 5ppm ammonia, and do I start making more frequent water changes? I haven't actually found out what the endpoint is, is it when 5ppm ammonia oxidizes entirely to nitrates within 24hrs, leaving no dectable ammonia or nitrites? It seems a bit extreme. Any advice?

Again, in summary:
NH3 processed at 2ppm/day
NO2 processed at 3.5ppm/day

-Fastfish

 

[JSchmidt]

Some people reduce to half the level of ammonia when you start showing nitrites. In your case, that would mean dosing the tank to 2.5 ppm ammonia rather than 5 ppm.

Personally, I've always dosed to 5 ppm throught the fishless cycle. Unless you're planning to heavily stock the tank, that might not be necessary.

It seems clear that you've got a pretty good populations of ammonia-oxidizers and your nitrite-oxidizers are coming along, too. If it were me, I'd be patient and not run any risks at this point. My guess is that, in another week, you'll be able to process 4 or 5 ppm ammonia completely in 24 hours. If you haven't bumped up the temp in the tank to 82 degrees F or so, you might want to. That usually speeds things up.

Hang in there...

Jim

 

[daveedka]

Agreed with Jim, You will easily reach a point where you can reduce 5 ppm to 0 in 24 hours with no visible nitrites at that time as well. and once the bacteria get going things will speed up considerably. the bacteria that eat nitrite seem to show up all at once. As was said many people cut their ammonia dosing in half but Like Jim I just kept mine between 4-5 ppm throughout. I currently do the same thing with my q-tank until I decide what exactly I'm going to do.