Overdose In Fishless Cycling

[Neptunienne]

Hello!

I've been cycling a 10 gallon tank without any fish and with the help of pure ammonia. I've done this before and it's gone smoothly, but unfortunately this time I miscalculated somewhat - didn't have an ammonia test kit at hand (still don't, actually - I used to have an ammonia indicator in my tanks for a while, and never saw any spikes; now my tests are past their sell-by date, need some new ones). When I came to this site and finally found the calculator (yay!), I found that I overdosed the tank with ammonia by about 3-4 times the recommended dosage. Oops.

Well I have nitrites now, and tons of them. My test kit reads up to 10 ppm and it was absolutely off the charts when I last tested. Nitrates were also off the chart (which means, yay, the cycle is drawing to an end). So I did a 75% water change, which brought my nitrites down to around 10ppm.

So far so good. I'll obviously drastically lower the quantity of ammonia I add to the tank, but I was wondering if my tank will be able to support enough bacteria to get rid of 10ppm of nitrites, or if I still need to dilute them some more to give the nitrifying bacteria a chance. I'd rather not be still trying to cycle this tank by next Christmas.

Does anyone have experience with this? Any advice?

Thank you!

 

[Colin_T]

the bacteria will grow sufficient numbers to break down whatever ammonia and nitrite is in the water on a regular basis.

Don't bother testing for nitrates because nitrate test kits will also pick up nitrite and give you an incorrect reading.

Leave the tank to run and it should settle down in a couple of weeks.

 

[rdd1952]

Don't bother testing for nitrates because nitrate test kits will also pick up nitrite and give you an incorrect reading.

I've never heard that. Do you have some evidence on it? To the best of my knowledge, a nitrate test will only show nitrate. You have to test nitrate to make sure that some nitrite is being processed. Otherwise, you are just hoping it is processing and would not have a clue if the cycle had stalled or not.

The tank will eventually cycle but you may want to do a large water change to get the nitrite down to a readable level. That will also allow you to test the nitrate and see what the reading is so you can monitor it also.

 

[Colin_T]

Don't bother testing for nitrates because nitrate test kits will also pick up nitrite and give you an incorrect reading.

I've never heard that. Do you have some evidence on it? To the best of my knowledge, a nitrate test will only show nitrate. You have to test nitrate to make sure that some nitrite is being processed. Otherwise, you are just hoping it is processing and would not have a clue if the cycle had stalled or not.

read the directions on the box or read a few books because it is common knowledge here. It usually says nitrate test kits will pick up nitrite and you have to take one from the other to get a correct reading.
Nitrite and nitrate are very similar and the nitrate test kit picks up both.
You can tell if the nitrite levels have stalled by whether or not the levels change over a few days.

 

[Shrimper]

It might depend on the test kit you have...

I'm certain when i cycled my tank last year the Nitrate levels only went up when the Nitrite levels went down.

Edit: just checked the instructions with my API master test kit and it makes no mention of the Nitrate test detecting Nitrite. It does say some tests will look for NO2-N and NO3-N instead of NO2- and NO3- which will give different results to this kit.

 

[waterdrop]

Neptunienne,

Regardless of how the above debate turns out about the test kits (and it -is- an interesting question) I would guess that both Colin & RDD1952 would agree with RDD's second paragraph, ie...

There's nothing wrong with repeated large water changes during fishless cycling.

In fact, my take is that they are quite good. You just turn off the filter and heater, change out as much water as possible, using dechlor & rough temp matching and then you have another opportunity to get the ammonia level recharged to the desired amount (ideally 5-6ppm if you are in the initial stage, 4ppm if you have already had your nitrite spike.)

Warming the temp somewhat beyond normal tropical fish temps is recommended by RDD but that lowers oxygen somewhat and so surface agitation is also recommended to keep the oxygen levels as high as possible. Water movement, high oxygen, pH of 7.5-8.6, ammonia level of 4-6ppm all seem to be recommendations for ideal development of the two types of bacteria desired.

~~waterdrop~~

 

[backtotropical]

Edit: just checked the instructions with my API master test kit and it makes no mention of the Nitrate test detecting Nitrite. It does say some tests will look for NO2-N and NO3-N instead of NO2- and NO3- which will give different results to this kit.

Nutrafin test doesn't mention detecting nitrite either. Which test kit are you referring to, Colin?

 

[rdd1952]

You can tell if the nitrite levels have stalled by whether or not the levels change over a few days.

Once a fishless cycle is underway the nitrite will be off the chart high, probably as soon as the first 4 ppm of ammonia is processed as 1 ppm of ammonia yields 2.7 ppm of nitrite. So unless you are testing nitrate to see that it is rising (or doing large water changes daily to keep the nitrite below the max reading on the chart), you have no way of knowing whether any nitrite is being processed at all. I also checked my API kit and there is no mention of the nitrate kit showing nitrite. I couldn't find anything online that mentioned that either.

 

[waterdrop]

I seem to remember a thread (from way back in time I think) where somebody had success actually talking with someone at the API lab and they were nice in explaining something. Anybody else remember this? Seems like a possibility for this question of whether the nitrate test can give falsely higher readings in the presence of nitrite... not that I'm volunteering

 

[Neptunienne]

Thank you all for your replies!

So following the 75% water change, which brought nitrite down to around 10ppm, I retested the water 24 hours later (without adding ammonia)... to find nitrite through the roof again. So obviously there's still a lot of ammonia in there that needs to be processed. Will redo another large water change soon, and up the temperature to around 29°C (I hear it's counter-productive to go over 30°C) and move the power filter to get more surface agitation.

Once a fishless cycle is underway the nitrite will be off the chart high, probably as soon as the first 4 ppm of ammonia is processed as 1 ppm of ammonia yields 2.7 ppm of nitrite.

Ouch! Well that definitely explains the off-the-chart-spike, if there was too much ammonia to start with.

Regarding the test kit debate, I have also read that nitrites mess up the nitrate readings on some water tests, but it's not in my test kit instructions. How the science behind this idea works, I don't know! What I have read in a fishless cycling article is that if you're short on money, a nitrite test kit would suffice: you would know that your tank is ready if, after adding 5ppm of ammonia, your nitrite level is zero a few hours (?) later. So if the nitrate test does fail because it's skewed, you should still be safe with that method.

 

[backtotropical]

I seem to remember a thread (from way back in time I think) where somebody had success actually talking with someone at the API lab and they were nice in explaining something. Anybody else remember this?

I'm sure that was RDD1952?

 

[waterdrop]

"up the temperature to around 29°C (I hear it's counter-productive to go over 30°C)"

Interesting, where did you hear that? Anybody else hear that?

 

[rdd1952]

I seem to remember a thread (from way back in time I think) where somebody had success actually talking with someone at the API lab and they were nice in explaining something. Anybody else remember this?

I'm sure that was RDD1952?

I had an email correspondence with them about Ammo-Lock but not about their test kits (but I will email them again about it). I remember tmack discussing an issue he had with his nitrate test and a correspondence he had with them detailed in this thread. I've still not been able to find any data that mentions a nitrate test kit giving falsly high readings because of nitrite.

 

[waterdrop]

I seem to remember a thread (from way back in time I think) where somebody had success actually talking with someone at the API lab and they were nice in explaining something. Anybody else remember this?

I'm sure that was RDD1952?

I had an email correspondence with them about Ammo-Lock but not about their test kits (but I will email them again about it). I remember tmack discussing an issue he had with his nitrate test and a correspondence he had with them detailed in this thread. I've still not been able to find any data that mentions a nitrate test kit giving falsly high readings because of nitrite.

Great! Thanks so much for taking the lead, RD! Let us know if you find anything.

I also think the temperature thing is quite interesting. I know you were attempting to learn some things with trying fishless cycling in the high 80's, low 90's (F degrees) and I wonder how you've been feeling about that?

Hard to know what the trade-off is between higher temp vs. higher oxygen for optimal growth of these bacteria - at least I've never seen any direct info that would make it easy to know. Also hard to know which things in the recipe are more critical to the bacteria growth speed (eg. temp/oxygen vs. pH or other things) - all of this being speculation just about optimals, not necessities, as I think the fishless cycling process as you have helped spell out for all of us is very robust and if one just waits long enough, the formula will do its thing regardless of some things not being optimized.

 

[Neptunienne]

"up the temperature to around 29°C (I hear it's counter-productive to go over 30°C)"

Interesting, where did you hear that? Anybody else hear that?

I found it in another thread here, I haven't actually read any science about it (maybe the OP know more?). But you're right, it's a very hard balance to strike. I've also read in a fishless cycling article that adding ammonia may or may not inhibit the growth of the nitrobacter (I think?), which would explain why the nitrite spike lasts so long. Then again, when you see how much nitrite is produced by 4ppm of ammonia, I think there's nothing to be surprised about: if there's 2.5 times more nitrites than ammonia, would it make sense to say that nitrobacter would take longer to grow big enough to consume that much nitrite?

In other cycling news, I found some Seachem ammonia indicators in a closet and stuck them in my tanks (after checking they still worked). There was actually no ammonia in my tank anymore, so I've added 4 ppm's worth and I'm keeping an eye on it to see how fast it'll go down (live indicators are pretty cool like that).

It's been a while since I've cycled a tank, but I think I'm making good time... started about a week and a half ago. Nitrite and nitrate readings are ridiculous, though. The test's maximum range on the color comparison chart goes to medium pink. Well it's gone dark magenta for both. I think I can safely say it's still going to take some time to cycle.