Nitrite Levels In Fishless Cycle

[rhostog]

Fishless cycling with mature media. Ammonia is processing nicely, but nitrites now above 1.5 - I've just topped up the ammonia so expecting the nitrites to go higher before they drop. I've heard that high levels of ammonia can inhibit the bacteria, but not had that problem - so what about nitrites - how high should I let that go before doing a water change?

Thanks for any advice!

 

[OldMan47]

When it is so high that you have a hard time measuring it, you can bring nitrites back down with a big water change. I'm not sure it makes any difference to the cycle but it feels good to be able to know what is going on and be able to follow it.

 

[rhostog]

OK - thanks! The mature media has certainly speeded the ammonia processing; hoping the nitrite processing will be quick too, but it's useful to know that it won't be harmful to the cycle if the nitrite levels go up. You're right, it does help a lot if you can see them dropping and feel like you're making some progress!

 

[waterdrop]

I agree with oldman, this cycle will probably proceed quickly regardless.

I have, however, build up a hunch/feeling from all the cases we watch here that water changes in the second stage (the nitrite spiking stage) are often a good thing. They drop the nitrite levels, as discussed, and if you are also in the situaton where your tap water will help bring the pH up closer or in to the 8.0 to 8.4 range, that is good too.

In fact, an easy generalization is to avoid water changes during the first stage (while A-Bacs are building up), but to do water changes during the second stage (while N-Bacs are building up.)

(of course, no matter how much doctoring one does during fishless cycling, one gets the feeling the fishless cycling is laughing at you and will take however long its going to take, anywho!)

~~waterdrop~~

 

[rhostog]

Thanks for the encouragement - it's really good to have support!

It took me a bit by surprise yesterday: went out for the day and came home to zero ammonia, so had to do a quick top-up and hope the A-bacs hadn't starved - seems to have worked as they processed from 3 to less than 1 overnight. I'm very pleased as it was only day 3 - I knew mature media would speed things up but surprised how much.

I'm going to do a water change before topping up again, and expect the N-bacs to take longer to get established (while I'm waiting I can imagine them sitting around in the filter laughing at me )

 

[waterdrop]

There is a subtle detail about our "TFF Add&Wat rdd1952" fishless cycling method that beginners often miss: You only add ammonia ONCE within any 24 hour period. It doesn't matter if ammonia drops to zero within the 24 hour period, you don't top it up until you've reached your 24 hour mark again.

You have to remember that for every 1ppm of ammonia, the A-Bacs will produce 2.7ppm of nitrite (NO2) and if you pump too much ammonia in there you will be spiking such high levels of nitrite that your cycling will slow down because of the fact that N-Bacs don't like a high nitrite level.

Some people choose morning as their "24 hour top-up mark point" and others choose evening, doesn't matter, but you need to keep track of it and things will go more smoothly.

~~waterdrop~~

 

[rhostog]

Sounds like the A-bacs will normally survive a few hours with zero ammonia then? That's useful to know. I'm doing 'add and wait' - last night was my first top-up since the initial dose. We'll stick to the evening routine, as my daughter can help then - it's her tank after all, a reward for her good school report!

I'm planning a water change before topping up this evening to bring the nitrites down so I can see better what's going on with them. Using the Nutrafin liquid tests and find it's quite difficult to distinguish the shades of pink, easier if the numbers are lower. API kit for me next time I think - it looks easier to read the colours.

Thanks again for the good advice!

 

[waterdrop]

A-Bacs will survive many hours without ammonia. Beginners get way too worried about starving them.

 

[mark.w.jones]

If you're struggling to get a nitrite reading off your kit because the level is too high, you can get a rough one by mixing 50% tank water with 50% tapwater in your test tube, then doubling the reading you get from your nitrite test.

 

[waterdrop]

Leave it to the school teacher to make us feel silly for not thinking of that clever idea...

 

[mark.w.jones]

Unfortunately the school tank in my sig. is not looking quite so happy at the moment . Wasn't able to fertilise as regularly through the holidays and my lights failed for 2 weeks as well. Have had to chuck lots of plants out and restart. Unfortunately, greeline aquatics who I used to get all my plants from have gone bust. A**e!

 

[waterdrop]

ah yes, I've heard a lot of moaning from the UK side about greenline

..well just keep the sig pic in there as I like looking at it as it was

 

[rhostog]

Update: Well, fishless cycle finally completed.

Used a small amount of mature media from the community tank (couldn't fit much inside the small internal filter) and the ammonia was processing happily overnight after just 3 days. But it's taken another 12 days (including a couple of large water changes when the levels got high and a top-up of the mature media) to get the nitrites to zero. I was surprised it took that much longer - we seem to have very slow-growing N-bacs!

So I'm really glad I did a fishless cycle on this tank, even though I had mature media and it was tempting just to pop a couple of fish in - it would have been a nightmare trying to keep the nitrites down for that long with fish in there - with nitrite in our tap water, large water changes aren't even the ideal solution.

My daughter thinks it's really funny, remembering to feed the cats, the fish and the bacteria every evening - she's enjoyed helping with the tests, but wouldn't go anywhere near that stinky ammonia!

 

[waterdrop]

Thanks for the update rhostog! Its well known that the N-Bacs are often more than twice as slow to develop than the A-Bacs. In a way, its unfortunate because its a real "downer" to try and tell beginners just as their patience has already been pushed to the limit. It also doesn't pay to sound too pessimistic since the overall time really is so unpredictable. Just when you prepare someone for the long haul, their cycle zips to a finish and you look silly!

~~waterdrop~~