Help with fishless cycle - day 16 and still no nitrite

[ellejay]

Hello

I'm cycling my 64 litre tank following the guidance on the sticky thread (which is brilliant, I've learned loads). My pH is 7.4, temp 25 degrees. I dosed on Day 1 with 2ml ammonia (in hindsight I should have used 1.8ml when accounting for substrate etc), I then tested 30 minutes later which confirmed the ammonia was 2-4ppm, using the API freshwater master test kit.

I've been testing for ammonia and nitrite every 3 days. Ammonia dropped fairly quickly - on day 4 it was down to 1.0ppm, day 7 0.25-0.5ppm, day 10 and 13 between 0 and 0.25 ppm (I think I was being generous though), and day 16 (today) it's 0. Still no nitrite.

I changed my substrate on Day 10 after I'd tested the parameters as I needed to change to sand. This probably included about a 30% water change. However given that the ammonia had already dropped I'm not sure if that really made much difference.

What am I doing wrong? Should I redose with ammonia? Aside from the initial dose I haven't added anything else as the parameters haven't matched the cycling thread, which says I should have seen nitrate after about 7 days.

Thanks in advance

 

[Colin_T]

I'm not sure what you read that says there should be nitrates after 7 days but most filters take 4-6 weeks to cycle and some can take longer. It normally takes 2-3 weeks for the first group of bacteria to build up in sufficient numbers to convert ammonia into nitrite. Then it takes another 2-3 weeks for the second group of bacteria to build up and convert nitrite into nitrate.

If you are on day 16 you are only half way through the cycling process.

 

[ellejay]

I'm not sure what you read that says there should be nitrates after 7 days but most filters take 4-6 weeks to cycle and some can take longer. It normally takes 2-3 weeks for the first group of bacteria to build up in sufficient numbers to convert ammonia into nitrite. Then it takes another 2-3 weeks for the second group of bacteria to build up and convert nitrite into nitrate.

If you are on day 16 you are only half way through the cycling process.

Apologies, misspelling, I meant nitrites - the sticky thread says they should have appeared by now. I'm not bothering to test for nitrates yet.

 

[Colin_T]

You can increase the temperature to 28C and increase the aeration/ surface turbulence too. The filter bacteria grow faster in warm oxygen rich water.

Try doing a 75% water change using dechlorinated water and add some ammonia. See how long it takes for the ammonia to drop to 0. If the ammonia does drop then you should get a nitrite reading.

 

[ellejay]

You can increase the temperature to 28C and increase the aeration/ surface turbulence too. The filter bacteria grow faster in warm oxygen rich water.

Try doing a 75% water change using dechlorinated water and add some ammonia. See how long it takes for the ammonia to drop to 0. If the ammonia does drop then you should get a nitrite reading.

Thanks, I'll give it a go

 

[ellejay]

Well I tested last night and I finally have nitrite, hooray! Never been so happy to see purple

I want to get some plants in there before I stock it with fish, can I put them in now or will it upset the cycle?

 

[Colin_T]

wait a couple of weeks before adding plants so you don't mess up the filter cycle.

don't add any fish until it has finished cycling.

 

[ellejay]

wait a couple of weeks before adding plants so you don't mess up the filter cycle.

don't add any fish until it has finished cycling.

Ok will do, thanks.

Don’t worry I’m nowhere near adding fish yet.

 

[steelo]

Well I tested last night and I finally have nitrite, hooray! Never been so happy to see purple

I want to get some plants in there before I stock it with fish, can I put them in now or will it upset the cycle?

Believe me, soon you will get sick of purple =) I'm in the last phase of the cycle and it seems to be taking an eternity. I'm to the point where nitrites are consumed in about 48-72 hours but nitrates are still very low (between 5-10 ppm).

 

[eaglesaquarium]

I doubt your nitrates are as low as you are indicating steelo.

1 ppm ammonia (as measured by API and most other brand hobby test kits) produces 2.7 ppm nitrite (again, as measured by most hobby test kits), which will then convert to 3.6 ppm nitrate (once more, on hobby test kits).

So, that means that only 2-3 ppm ammonia total has been processed? That seems unlikely. The more likely outcome is that you are getting a false 'low' from the hobby test kit. The nitrate test (bottle #2 for API) has TWO reagents in it. One remains in solution, whereas the other is a precipitate and settles to the bottom. The directions are to really mix that one for 30-60 seconds. I'd recommend bashing it on a hard surface a few times (to loosen any that might have hardened) and then shake vigorously for at least 2 full minutes. Chances are, you'll see a significantly higher result.



As for the OP... the 'should' of when things 'should' happen will vary from tank to tank. There's far too many variables at play for any article like our posted cycling thread to predict results. Your tank seems to be a slow cycler. That happens from time to time, especially in soft water conditions. You haven't provided the kH or gH values for the tank, but these can and will affect cycling duration. I would predict that your values are fairly low given your results. OR... that your tap water has very very low levels of the needed bacteria in it.

Either way... keep a close eye on that pH. If that drops (which it can as a result of nitric acid building up - nitrates), that can indicate a stall in your cycle... that indicates that the kH buffering capability of your water has been reached and the carbonates in the water have been consumed by the bacteria and they can no longer do what they do. If that happens... a quick full water change is the solution and things will kick back up in a day or so.

 

[steelo]

I doubt your nitrates are as low as you are indicating steelo.

1 ppm ammonia (as measured by API and most other brand hobby test kits) produces 2.7 ppm nitrite (again, as measured by most hobby test kits), which will then convert to 3.6 ppm nitrate (once more, on hobby test kits).

So, that means that only 2-3 ppm ammonia total has been processed? That seems unlikely. The more likely outcome is that you are getting a false 'low' from the hobby test kit. The nitrate test (bottle #2 for API) has TWO reagents in it. One remains in solution, whereas the other is a precipitate and settles to the bottom. The directions are to really mix that one for 30-60 seconds. I'd recommend bashing it on a hard surface a few times (to loosen any that might have hardened) and then shake vigorously for at least 2 full minutes. Chances are, you'll see a significantly higher result.



As for the OP... the 'should' of when things 'should' happen will vary from tank to tank. There's far too many variables at play for any article like our posted cycling thread to predict results. Your tank seems to be a slow cycler. That happens from time to time, especially in soft water conditions. You haven't provided the kH or gH values for the tank, but these can and will affect cycling duration. I would predict that your values are fairly low given your results. OR... that your tap water has very very low levels of the needed bacteria in it.

Either way... keep a close eye on that pH. If that drops (which it can as a result of nitric acid building up - nitrates), that can indicate a stall in your cycle... that indicates that the kH buffering capability of your water has been reached and the carbonates in the water have been consumed by the bacteria and they can no longer do what they do. If that happens... a quick full water change is the solution and things will kick back up in a day or so.

I didn't mean to get this discussion off topic. I believe I'm on the last leg of cycle and have only been bringing the ammonia levels up to about 1 ppm as to avoid the nitrites getting out of control. So far, I have only added ammonia twice after doing a huge water change. I'm hoping the nitrates multiply pretty quickly, but I'm not seeing much progress yet. Nitrates still appear to be holding steady between 5-10 ppm, but the test might be wrong. At least I know ammonia and nitrites disappear after about 48 hours, so I there must nitrates consuming the nitrites.

I agree with you about there being no 'timetable' I've been at this for over 2 months and it's been agonizing. There are other posters who were able to cycle in 1-2 weeks, it really depends on a lot of factors and everybody's tank is different.

 

[eaglesaquarium]

The nitrates are definitely there, or you have a ton of plants that are sucking them up. My money would be on the test results being wrong. That test is easy to get 'wrong', because we get complacent in the shaking, because early tests the precipitate is more mixed... but as time goes on, it settles and locks in a bit more.

 

[steelo]

The nitrates are definitely there, or you have a ton of plants that are sucking them up. My money would be on the test results being wrong. That test is easy to get 'wrong', because we get complacent in the shaking, because early tests the precipitate is more mixed... but as time goes on, it settles and locks in a bit more.

Hi, yes I know I must have nitrates because the nitrites are disappearing and I do not have any plants. I tested the nitrites again last night and they were at about .5 ppm (ugh SO close!) after adding 3 ppm ammonia the night before. Ammonia was at 0, and nitrates were between 10-20 ppm (I also beat the heck out of the nitrate test kit to make sure it's working correctly) It would appear that it's processing very close to 2-3 ppm nitrites in 24 hours

I don't know what the heck I was thinking last night and accidentally added twice the ammonia dose I was supposed to. I checked the ammonia level and it was between 4-8 ppm...not crazy high, but I really hope my stupidity didn't screw things up.

I'm thinking though that if anything, it will just take longer than 24 hours for the nitrites to convert the large amounts of ammonia and the nitrates to do their job. I know I have nitrates so I'm hoping that the nitrites won't go out of control again. Once everything is at or near zero again, my nitrates should be sky high. At that point, I'd imagine the tank should be able to process any ammonia and nitrites my future fish produce. With any luck, I will be able to do a huge water change tonight or tomorrow, wait 24 hours and it should be ready for fish!

 

[eaglesaquarium]

Seems so, steelo.

FYI, if that ever happens again, you can feel free to remove about 50% of the water and refill with no ill effects to the cycle.

 

[steelo]

Seems so, steelo.

FYI, if that ever happens again, you can feel free to remove about 50% of the water and refill with no ill effects to the cycle.

Thanks for your help. I just tested nitrites after 24 hours...they are at least 5...ugh. I didnt expect the nitrates to be able to process that many nitrites though in just a day. I added about 6ppm ammonia by accident yesterday and Im sure nitrites are at least 10 ppm now. Good news is nitrates are up to around 40 ppm. Should I do a 50% water change or just wait it out? Last thing I want is to stall the cycle when I'm 90% there...Thanks!