Hi again. I have a ten gallon tank with two new Orandas. I wasn't able to start the tank cycling before I got the fish (although before they make the move home to a new 30 gallon, I will get that tank cycling.) For now, I'm watching the water quality and trying to keep things under control. I know, of course, that frequent partial water changes will reduce the build-up in the water, but might also slow cycling. So how much Ammonia (or Nitrite) is too much for the fish to handle? In other words, what's a good middle ground between keeping the fish safe and starting the tank cycling more quickly? How much water should I cahnge in a partial change? Also, what do you folks think about those products that claim to add beneficial bacteria to the tank, kick-starting it? Are they safe when fish are already present? Do they work?

Thanks again for your help. This board is a great resource for anyone new to Goldfish like myself.

Jeff Kirsch

Hi Jeff

You should aim to keep the ammonia and nitrites between 0.5 and 1.0 ppm. This is a safe level for your fish and still allows the bacteria to grow. As for water changes, change however much is necessary each day to keep the ammonia and nitrites at this level; that might be 50%, 20% or none at all. When you do a water change, don't assume you've changed enough - test again to be sure the levels are 1.0 or less.

The only bacterial product which actually kick-starts a cycle is Bio-Spira from Marine Labs; the others - like Stress Zyme and Cycle - are pretty much useless. Al are safe to use with fish in the tank already however.


Hope this helps.

If you cannot find BioSpira, don't bother wasting any money on stress zyme, I tried it (twice), and it did absolutely nothing. I can't say I've personally tried cycle, but I've heard its pretty much the same and would not spend my money on that either.

personally, I find cycle is pretty useless, even the "new and improved" cycle. I dumped in 2x the recommended amount (it said more doesn't hurt, so I'm like what the heck) and I threw in some ammonia. It took 7 days for nitrites to even start showing at all. I don't think that stuff works at all..