Fishless cycle with ammonia - when to do water changes?

Hello! I am mid cycle (fishless) on my 10ga that is a planted tank. I have been using ammonia dosed at around 4.0ppm. about a week in I got nitrite spikes, showing around 5.0+ ppm, and now a few days later I have had Nitrates present, but they are off the chart at 180+ ppm. Ammonia is between 0 and .25 by the next morning, but nitrites aren't falling yet.

I've read several places to not change the water mid cycle, just want to confirm this? Wait till nitrites are showing zero, then do a water change and test the cycle by dosing with ammonia again? Just want to make sure Nitrates being this high are okay?

 

Hello! I am mid cycle (fishless) on my 10ga that is a planted tank. I have been using ammonia dosed at around 4.0ppm. about a week in I got nitrite spikes, showing around 5.0+ ppm, and now a few days later I have had Nitrates present, but they are off the chart at 180+ ppm. Ammonia is between 0 and .25 by the next morning, but nitrites aren't falling yet.

I've read several places to not change the water mid cycle, just want to confirm this? Wait till nitrites are showing zero, then do a water change and test the cycle by dosing with ammonia again? Just want to make sure Nitrates being this high are okay?

Since there is no inhabitants, it will be fine. I would dose again with Ammonia again.
My usual tactic is dose ammonia to about 3ppm, wait until it gets to 0, dose again, wait till 0, and repeat until this happens within a 24 hour period. Once that starts happening, I continue, but now I start testing nitrites and wait for both to clear in a 24 hour period. Once that happens then I usually drop down to a 90% water change, and do it again a few times, 50% water change (or whatever makes the nitrates about in range for fish). Once I can get a good rhythm going, I know then its time to add fish 24 hours after my last dose.

Took me 2 weeks on my 210, but I used bottled bacteria (no idea if it did anything to help though). I am doing this now on my 75g FOWLR tank waiting for the rock to start doing its job.

 

It is recommended not to allow ammonia or nitrites to go over 5 ppm. There’s a video from Dr. Tim explaining why I forget the exact reason. I think at some point a different kind of bacteria shows up which isn’t beneficial and the process will stall.

I always keep mine at 5 right until the end until I can’t anymore (because it zeros out by the next day).

Then once that happens I dump 5ppm ammonia in all at once and make sure it’s 0/0 by the next day to know the tank is done/ready.

Just my process. I feel it’s better to have BB starve and die off because it’s not needed rather than Nitrites and Ammonia spike because there is not enough during cycling which often will happen in a fish in cycle since fish certainley can’t handle 5 ppm.

 

It is recommended not to allow ammonia or nitrites to go over 5 ppm. There’s a video from Dr. Tim explaining why I forget the exact reason. I think at some point a different kind of bacteria shows up which isn’t beneficial.

I always keep mine at 5 right until the end until I can’t anymore (because it zeros out by the next day).

Then once that happens I dump 5ppm ammonia in all at once and make sure it’s 0/0 by the next day to know the tank is done/ready.

Just my process.

I think the *rumor* I heard is that around 5 it starts to actually kill the beneficial bacteria.. So maybe that bad bacteria kills the good one?

 

I think the *rumor* I heard is that around 5 it starts to actually kill the beneficial bacteria.. So maybe that bad bacteria kills the good one?

Could be. Though I don’t think it ‘attacks’ the beneficial bacteria, more so takes/uses it’s food away from it which is the same result. In any case it will stall the process. I have a lot of respect for Dr. Tim so I take it as more than just a rumor. But that is not to say an entire cycle or process would be destroyed by doing so, we’re talking in terms of an ideal scenario/process not a mandatory one.

I have not tested anything outside my 5 ppm method as it has worked so well for me so I honestly cannot say what would happen with first hand experience.

 

Could be. Though I don’t think it ‘attacks’ the beneficial bacteria, more so takes/uses it’s food away from it which is the same result. In any case it will stall the process. I have a lot of respect for Dr. Tim so I take it as more than just a rumor. But that is not to say an entire cycle or process would be destroyed by doing so, we’re talking in terms of an ideal scenario/process not a mandatory one.

I have not tested anything outside my 5 ppm method as it has worked so well for me so I honestly cannot say what would happen with first hand experience.

The *rumor* I heard wasn't from Dr. Tim's so that's why I used that as a "rumor". I would definitely give it more credit as well based on something actually said by Dr Tim.

 

As long as the ammonia you are adding is going down to or close to zero within 24 hours of adding it your cycle is still moving forward. As long as you dechlorinate and temp match the fresh water, doing a water change to get both nitrites and nitrates down to readable levels isn't going to affect the cycling process so I do recommend you do one.

Personally I wouldn't be adding as much ammonia as you are adding. I would cut the amount down to 2ppm until the cycle is complete. There is no way you can add enough livestock to this tank to need that much bacteria. It is having to work harder than necessary right now trying to process this much ammonia to nitrites and nitrites to nitrates.

 

Thanks for all of the replies! I did step back the ammonia to about 2ppm, and now both Nitrites and Ammonia are clearing in less than 24 hours. Nitrates are at about 80ppm after 2 90% water changes. I'm going to keep stepping that down till I get the nitrates at or below 20ppm, and continue dosing a little ammonia until it's done. I only have 1 betta going in the tank and it's heavily planted so it will be a small bio load.

I tested my two water again today and it's at .5 ppm ammonia which is high, although could be chloramine since it's city water, but as long as the cycle is working correctly, shouldn't be an issue. I'm dosing with a standard dechlorinator now for water changes, but once I bring the little guy into the new tank, I will probably use Prime for water changes

 

FYI, any nitrite present will mess with your nitrate test kit. So, you can't necessarily believe a high nitrate reading if your nitrite isn't zero.

 

Got his Mopani driftwood in and a few more plants today. Going to change the water a few more times and hopefully be ready to go here in a week or so

 

FYI, any nitrite present will mess with your nitrate test kit. So, you can't necessarily believe a high nitrate reading if your nitrite isn't zero.

This is a new one for me. Personally I've never experienced this nor have I ever even heard of it happening. We are all here to learn though so please let me know what leads you to say this.

Got his Mopani driftwood in and a few more plants today. Going to change the water a few more times and hopefully be ready to go here in a week or so

I love where you are going with this tank. When those plants start growing they are really going to look good in there.

 

This is a new one for me. Personally I've never experienced this nor have I ever even heard of it happening. We are all here to learn though so please let me know what leads you to say this.

The way most nitrate kits work is a reduction method, usually using cadmium. Nitrates are reduced to nitrite, which reacts with an indicator.

https://archive.epa.gov/water/archi...tion method is,the original amount of nitrate.

 

FYI, any nitrite present will mess with your nitrate test kit. So, you can't necessarily believe a high nitrate reading if your nitrite isn't zero.

Really? So if nitrite is present u sold not test for nitrate?

 

Really? So if nitrite is present u sold not test for nitrate?

Just be aware that if nitrate seems higher than you expect, and there is any measurable nitrite, then you are getting some interference.

To me, when cycling, it just makes sense to test for ammonia and nitrite. But... many ways to skin a cat.

 

Just be aware that if nitrate seems higher than you expect, and there is any measurable nitrite, then you are getting some interference.

To me, when cycling, it just makes sense to test for ammonia and nitrite. But... many ways to skin a cat.

This is actually good advice and I am glad you clarified for those that read the original post and might get concerned or confused. I agree, when cycling the ammonia and nitrite readings are the ones to keep an eye on. An occasional pH and nitrate reading is a good idea since cycling can cause a drop in pH and seeing nitrates lets us know things are moving forward.

 

FYI, any nitrite present will mess with your nitrate test kit. So, you can't necessarily believe a high nitrate reading if your nitrite isn't zero.

Haven't heard this before, but it makes a lot of sense.. I don't know that I've ever noted one way or another, as usually only time I have nitrite, I'm cycling and only care about getting it to 0, and dont bother testing nitrate then.

Always love learning new stuff!