reg said:
Thank you so much for your help.I did not begin to test the water until the tank had been set up for a week with fish in it. The water was a little cloudy the first few days and now it is really clear. Does cloudy water have any correlation with cycling stages? I read somewhere (maybe in my water testing kit?) that 40 is an acceptable number for nitrates and when nitrates were present at this level it was a sure thing that your tank had cycled. Is this incorrect? What are the nitrate levels on a well established tank? I did add about 100 lbs of the cichlid sand that was packed in bacteria rich water and also added a bacteria product purchased at the pet store. Thanks again.
Hi Reg. 40 is probably a little on the high side of "normal" for an established tank. Some people try to keep their Nitrate under 20. Other people have 20ppm of nitrate in their tapwater so their's is by necesity higher.
A cycle is "complete" not when the nitrate reaches a particular level, but rather when ammonia and nitrite are gone. Keep in mind, though, that if you increase the bioload you may go through a "mini-cycle", where the bacteria can't keep up with the new bioload until they have a chance to multiply. For this reason some people add fish a few at a time.
You can also do a "fishless" cycle using ammonia where you duplicate the ammonia production of your full bioload and then you can add all your fish at once after the cycle is complete.
If it were my tank, I wouldn't let my nitrate get above 40, and I'd try to keep it closer to 20. It may be worth testing your tapwater though so you know if you're handicapped by nitrate in your tap.
I wouldn't expect 8 small fish to put much of a dent into ammoniafying 135 gallons of water, you may need to either switch to a fishless cycle or put in some more cycling fish, or simply be patient and wait for them to produce some more ammonia!
-Rick (the armchair aquarist)