End of cycle Questions

Rcj520

New member
Well it looks like my cyxle just finished. Taking a few days to keep testing and make sure. But ammonia and nitrites are at zero. I can process ammonia from 4ppm to 0 within 24 hours. My nitrates are through the roof. Reads somewhere between 80 and 160 on my API test kit. Is it time for a large (75%) water change? And fish or cuc first? I have some brow algea with about 30-40% coverage on my rocks.
 
Well it looks like my cyxle just finished. Taking a few days to keep testing and make sure. But ammonia and nitrites are at zero. I can process ammonia from 4ppm to 0 within 24 hours. My nitrates are through the roof. Reads somewhere between 80 and 160 on my API test kit. Is it time for a large (75%) water change? And fish or cuc first? I have some brow algea with about 30-40% coverage on my rocks.


I am dealing with the same issue. I was advised to do a 100% water change. I started with dry rock though so there is really no life on the tank. I just finished making water and am planning to do a water change this weekend.
 
There is a lot of misinformation floating around that has newcomers adding ammonia multiple times during the cycle which only adds to the duration of the cycle and leaves you with very high nitrates at the end of the cycle, sounds like you may have fallen into that trap. I would make a 100% water change before you add your CUC. Chances are your rock will have absorbed some of the nitrates, so you may be battling high nitrates for awhile, but by making larger than normal water changes over the next few weeks you should be able to get the nitrates down. In the future a 2ppm ammonia level is plenty high for the cycle, add ammonia only once (the bacteria can live for over a year without more ammonia, you do not need to worry about them starving) and perhaps one more time at the end of the cycle if you absolutely have to know if the bacteria can handle a bio-load, but really if you nitrites zero out the bacteria is there and there is usually no need to recheck. The ammonia has to go somewhere and unfortunately it is in the form of high nitrates in our tanks.
 
yeah, this thing where you keep adding ammonia is jacking people up. I can see why you'd want to test once to make sure the cycle is done, but more than that is uneccesary. The bacteria that remove nitrates take a little longer to develop, so they just haven't caught up yet.

Lucky for you it's easy to fix with a big water change. And you don't need to worry about the rocks absorbing nitrate and leaching it later. That's a myth. More here: http://www.reefcentral.com/forums/showthread.php?t=2029597
 
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I have high nitrates and only dosed to 2 ppm. I did throw a couple pinches of food in after the fact. But nothing crazy.
 
In freshwater planted tank, the general cycling method is to maintain 2ppm ammonia till you can clear it in 24 hrs. For FW planted tank, nitrate up to 40ppm is normal and don't need water change. So perhaps fw->reef convert take the same practice over.
 
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