9 Weeks And Still Not Fully Cycled

[yabadaba]

Guys, as of yesterday my fishless cycle has now been going for 9 weeks, but the nitrite is still not being cleared within 12hrs. I re-dose with ammonia every 24hrs and the ammonia clears in under 12hrs, but if I test at the 12hr point I get a reading of approx 0.25ppm for the nitrite. It finally reduces to zero at about the 18-20hr stage and has reliably been doing that for several weeks now, so progress through the cycle basically seems to have stalled.

I've been adding bicarbonate of soda every now and again to keep the pH up ever since it started crashing at around week 6 and I have the temperature at 28°C.

I'm thinking maybe I should raise the temp higher to say 30°C and add an airstone? Any suggestions for helping speed things up would be very much welcomed, or do I just require an extra dose of patience?

 

[Dogson]

Firstly well done for pursuing the fishless cycle for that long most would have chucked fish in by now! How often do you do water changes?

 

[yabadaba]

Firstly well done for pursuing the fishless cycle for that long most would have chucked fish in by now! How often do you do water changes?

Cheers. To be honest, I've only done one water change as I didn't think you needed to unless the pH crashes....which it did. Since doing that one the pH has dropped down again, but I've then been adding bicarbonate of soda, as that's the easier remedy! You think I should start doing regular water changes?

 

[waterdrop]

Yabadaba,

I might help to think about context. The colonies and biofilms are still maturing at 6 months and even 1 year.

Any method of fishless cycling is just a set of hobbyists trying to create a methodology for determining the point at which you have matured the two colonies such that the risk of mini-cycles when you introduce the first big stocking of fish is quite low. Its all going to be very imperfect. The choosing of "12 hours" and watching that for a week was just a bunch of us on this forum noticing that that seemed to constitute a good dividing line between a lot of our cases that seemed to always have success vs. a lot of cases that didn't, but its still a blurry line!

The fact that your N-Bac colony is taking 18 hours or so to fully clear the nitrite currently may not be significant to you, it just depends on your stocking plans. Your particular N-Bac colony may just be a little slower making its way down the path toward that 6 month type maturity. Take a hard look at your stocking plan. Its pretty rare for people to want -all- fish that are able to be in an initial stocking. In my case I very much wanted neon tetras for instance and of course one shouldn't even give a thought to stocking those prior to 4 to 6 months, so that cut down the initial stocking right there! If your stocking is really only going to be about 3/4 of the 1-inch guideline region then there should be nothing wrong with a filter that's clearing the last 0.25ppm of nitrite only between 12 and 18 hours I'd think.

The only cost to you of not getting fully out to the 1-inch stocking is that once you switch your water over to fish and start running the tank normally, you will forever after be subject to the normal small additions of fish (2 or 3 fish depending on size, you know what I mean I think.) For most people that's not a big deal because they are so busy enjoy the 3/4 stocking of new fish anyway!

~~waterdrop~~

 

[yabadaba]

Yabadaba,

I might help to think about context. The colonies and biofilms are still maturing at 6 months and even 1 year.

Any method of fishless cycling is just a set of hobbyists trying to create a methodology for determining the point at which you have matured the two colonies such that the risk of mini-cycles when you introduce the first big stocking of fish is quite low. Its all going to be very imperfect. The choosing of "12 hours" and watching that for a week was just a bunch of us on this forum noticing that that seemed to constitute a good dividing line between a lot of our cases that seemed to always have success vs. a lot of cases that didn't, but its still a blurry line!

The fact that your N-Bac colony is taking 18 hours or so to fully clear the nitrite currently may not be significant to you, it just depends on your stocking plans. Your particular N-Bac colony may just be a little slower making its way down the path toward that 6 month type maturity. Take a hard look at your stocking plan. Its pretty rare for people to want -all- fish that are able to be in an initial stocking. In my case I very much wanted neon tetras for instance and of course one shouldn't even give a thought to stocking those prior to 4 to 6 months, so that cut down the initial stocking right there! If your stocking is really only going to be about 3/4 of the 1-inch guideline region then there should be nothing wrong with a filter that's clearing the last 0.25ppm of nitrite only between 12 and 18 hours I'd think.

The only cost to you of not getting fully out to the 1-inch stocking is that once you switch your water over to fish and start running the tank normally, you will forever after be subject to the normal small additions of fish (2 or 3 fish depending on size, you know what I mean I think.) For most people that's not a big deal because they are so busy enjoy the 3/4 stocking of new fish anyway!

~~waterdrop~~

Thanks. I've pretty much decided on south american Cichlids, so quite a heavy bioload. But I would only want to add a few at a time, building up the stocking over several months, so maybe I would be okay to start off with a couple of fish next weekend.