Fishless Cycle

[Sierrajuliette]

Hi all
I have been fishless cycling my tank for 4 weeks now, I am safely through the ammonia stage and nitrites are dropping - currently 0.25ppm however I don't wan to keep adding ammonia as I think I am so close to the end of the cycle, is it ok to add 4 of my guppies now?

 

[Aquascaper]

Nitrites are still toxic to fish, once the cycle is complete they are (simply speaking) immediately converted to Nitrates and therefore not an issue. The Nitrite phase is sometimes quite long so, having come this far, you'd be best to wait until the cycle completes return than risk undoing all your good work.

 

[brian1]

I would say yes,providing your ammonia is 0

 

[Sierrajuliette]

Lol ok I ave one yes and one no! I'm still on the fence then! My ammonia is 0 btw further debate needed from all you fish experts!

 

[Xraymark]

How much ammonia are you adding and how quick is it clearing?

 

[brian1]

I would just like to know from Aquascaper how you keep the present bacteria fed,would it not be better to add fish now than more ammonia, as fish poop and food should do the job???

 

[mossonthemoon]

Personally I would wait until you get to zero nitrites. It is the safest option and it means you aren't risking turning all of those weeks into a waste of time.

As to the above question, you would keep adding ammonia to 2ppm and letting it drop to 0 until nitrites are also 0. The tank should be taking care of 2ppm of ammonia in around 12 hours if you are fully cycled, so it shouldn't be too big of a deal to keep doing that. If you are truly at the end of the cycle then it really won't be long before you get to that 0 nitrites landmark.

 

[Sierrajuliette]

I was adding 4 ppm of ammonia which dissapeared in 48hrs (went through this process twice to check it was correct), stopped adding ammonia last Thursday, nitrites went up to 2 ppm and nitrates to 40ppm, did a 50% water change on Saturday, nitrites were 1ppm yesterday and 0.25 ppm today.

 

[mossonthemoon]

Did you change the water until the ammonia was 0 before you stopped adding it? I don't know how long the bacterial colony lasts without a food source, so it may be riskier still to add fish. You should be bringing the ammonia back up to ~2ppm up until 24 hours before you get your fish, and that 2ppm should clear in around 12 hours. Logically, that would mean 4ppm should clear in 24 hours.

 

[Aquascaper]

I would just like to know from Aquascaper how you keep the present bacteria fed,would it not be better to add fish now than more ammonia, as fish poop and food should do the job???

Until the cycle is fully complete (0 ammonia, 0 nitrites and rising nitrates) you continue to add your ammonia source. Once the cycle is complete you carry on adding ammonia, stopping on the day before you add fish. On 'fish day' you do a total water change (as much as possible) to clear out any residual ammonia and then add the fish. That way the filter continues to cope with 'x'ppm ammonia until the fish are in and then adjusts to the bioload of your stock. This is why you can add a full stock in one go rather than in increments as with a fish-in cycle.

Adding fish now would be no better than doing a fish-in cycle, there are still toxins in the water (nitrites) not being processed by the filter media so you would have to start doing massive daily water changes to keep the fish healthy. The whole point of a fishless cycle is to avoid this hassle (and to avoid killing/harming fish obviously).

 

[RossC]

Aquascaper is correct, wait for the fish this is still an essential part of the fish-less cycle. Keeping adding ammonia you need to keep those bacteria fed. Yes the Nitrites might increase again a little but they will eventual catch up trust me. I used this exact method with all 4 of my tanks and it was definitely worth the wait.

 

[Xraymark]

I was adding 4 ppm of ammonia which dissapeared in 48hrs (went through this process twice to check it was correct), stopped adding ammonia last Thursday, nitrites went up to 2 ppm and nitrates to 40ppm, did a 50% water change on Saturday, nitrites were 1ppm yesterday and 0.25 ppm today.

Too early to add fish. You will just end up in a fish in cycle with water changes. Just stay the course particularly as your ammonia was dropping.
Here's how I do my fishless cycle. Initial dose to 4ppm. Once that drops to zero dose to 1ppm. Keep doing that until nitrites rise and fall to zero within 12h. Only dose once in a 24h period. Then up the ammonia to 2, when it clears then up it to 3 ppm. Once your ammonia and nitrites clear in 12 h stock away. Keep temp at 28-30c and ph 8. The reason to keep ammonia dosing low initially is try and keep nitrites low as they take longer to process. Large water change that day to get rid of nitrates then add fish.
Every bodies cycle takes their own time, mines usually 3weeks.Good luck

 

[brian1]

Thanks for the explanation Aquascaper, very well explained......cheers