Fishless Cycling

[skyguy33]

Hi everyone,

After much reading on this and other forums, I am starting to get concerned about my fishless cycle. I started about 6.5 weeks ago with ammonia I found at Ace Hardware. I dosed my tank to 4ppm and waited a few days to begin water testing. About after a week, the ammonia had disappeared and, of course, nitrites, existed and nitrates were 0. I have fed the bacteria with more ammonia every other day or so with about 3 ppm. Nitrites have been unreadable using the API Freshwater Test kit (plus so many of the higher range nitrite numbers seem to be way too similar on the chart and I can't really tell the difference). I also tried a diluted test but that also comes out high on the chart and hard to discern. Anyway, I did a 60-70% water change, and the nitrite number was still pretty high (maybe 2 ppm, but could've been anywhere between 2-5ppm). It's been about 5-5.5 weeks now, and nitrates have been very low and stable at 5ppm and don't seem to really be increasing. Perhaps a stuck cycle? Any thoughts or recommendations? pH seems to be fine. Around 7.8.

Thanks for all of your guidance!

 

[Essjay]

It sounds as though you have added too much ammonia. This is turned into so much nitrite that it stalls the cycle. Unfortunately the stall point is off the top of the scale of our nitrite testers, so one of our members wrote a method which cannot produce enough nitrite to stall the cycle - provided it is followed to the letter. http://www.fishforums.net/threads/cycling-your-new-fresh-water-tank-read-this-first.421488/

If you read through the method in the link, you'll see that ammonia is only added when the readings have reached certain specific targets. The best thing you can do is to do big water change - as much as possible, then dose ammonia to 3ppm and follow the instructions in the link. Since you have already grown a lot of ammonia eating bacteria, the first part will go a lot quicker.

 

[FishGuest5123]

I totally agree and was going to say the same thing, essjay. You should dose ammonia to 3 or 4ppm and then wait for it to drop to .25 or less before dosing again. I dose ammonia according to what my bioload will be once my fish go in. For my Goldie’s who have large bioload, I dose to 4ppm. For my bettas and other tropicals, I dose 3ppm. For my shrimp tanks I only dose 2ppm. You did good to do a water change.

 

[skyguy33]

Thanks for the answers. So kind of an interesting situation. Over the next few days, nitrites dropped to zero and the nitrates were very high. In order to make sure it was done cycling, I added one last dose of ammonia. I tested it about 30 minutes after going in and it read 4 ppm ammonia, 0 nitrites, and about 80 ppm nitrates. About 24 hours later, I had .50 ppm ammonia, 0 nitrites, and nitrates were higher still. I waited another day and ammonia wouldn't go below .50 ppm ammonia, while nitrites all stayed at 0. I thought maybe it was my test kit, and brought a water sample to a LFS and they said that there was indeed ammonia in my tank. I'm totally confused because it was killing off all the ammonia before and now it seems like it won't do it anymore. Obviously, the bacteria is there because it reduced it from 4 to .5 and nitrites are all set because those still stayed at zero. Any ideas?

Thanks!

 

[Essjay]

If this was my tank I would do a large water change to reduce the amount of nitrate in there. If the reading is very high, something like a 90% water change. With this size water change, make sure the new water is dechlorinated and warmed to the same as the tank water. Then I would add 3 ppm ammonia (3/4 of the amount that gives you 4 ppm, no more than that) and see what the levels are like after 24 hours. If both ammonia and nitrite are zero, then either go get fish or if the nitrate level is higher than tap level, do another water change to get nitrate down to tap level, then go and get fish.
But if one or other (or both) is not zero after 24 hours, you would need to decide where you are in the method in that link I gave you and follow the method from that point.

 

[FishGuest5123]

I agree. A couple of water changes should fix it. I wouldn’t add ammonia all the way back up to 3ppm though. Maybe 2ppm.

 

[steelo]

Hi everyone,

After much reading on this and other forums, I am starting to get concerned about my fishless cycle. I started about 6.5 weeks ago with ammonia I found at Ace Hardware. I dosed my tank to 4ppm and waited a few days to begin water testing. About after a week, the ammonia had disappeared and, of course, nitrites, existed and nitrates were 0. I have fed the bacteria with more ammonia every other day or so with about 3 ppm. Nitrites have been unreadable using the API Freshwater Test kit (plus so many of the higher range nitrite numbers seem to be way too similar on the chart and I can't really tell the difference). I also tried a diluted test but that also comes out high on the chart and hard to discern. Anyway, I did a 60-70% water change, and the nitrite number was still pretty high (maybe 2 ppm, but could've been anywhere between 2-5ppm). It's been about 5-5.5 weeks now, and nitrates have been very low and stable at 5ppm and don't seem to really be increasing. Perhaps a stuck cycle? Any thoughts or recommendations? pH seems to be fine. Around 7.8.

Thanks for all of your guidance!

I'd do a 75% water change and leave it about a week without adding any more ammonia.

 

[FishGuest5123]

I wouldn’t go an entire week without some ammonia or fish food. The bacteria could start dying off.

 

[steelo]

I wouldn’t go an entire week without some ammonia or fish food. The bacteria could start dying off.

Naw, trust me the bacteria won't die off. If he's at 4ppm and changes out 75% he should still have some ammonia in there anyways. I thought my cycle was stalled too and did a huge water change and just left it. Almost magically, the nitrites went down to almost zero and the nitrates were at 20ppm

 

[FishGuest5123]

It actually should do that with just the water change.