what the crap?!? Cycle actually worked?

I started my tank with cycle and its been three weeks now, and after one initial amonia spike after startup, I just added an amonia pack to the filter, things are fine. My nitrites are a bit up today, but the fish seem ok, and are eating like ...umm fish. I added more cycle. I've done a 30% water change each 5 days or so and just keep adding the cycle. So, far so good.

Cycle probably contains (if you get a good bottle) some ammonia-eating bacteria, but not those that permanently inhabit the tank. The Cycle bacteria seem to have a rather limited lifespan, which I presume is why you have to re-dose the tank regularly.

It may be that some people's tanks develop enough permanent bacteria in the presence of the Cycle bacteria that ammonia spikes aren't seen. More commonly though, a spike is seen, seemingly out of the blue, several weeks after discontinuing use of Cycle. At that time, the tank experiences a cycle (or mini-cycle) as the true nitrifiers establish themselves.

Whatever the case, there isn't much doubt that the permanent nitrifiers we want are not in Cycle. Only BioSpira (currently unavailable) seems to contain the true nitrifiers. As such, many of us hold that Cycle is junk, and that it is good mostly for separating you from your money.

HTH,

Jim

It would be my guess, that the very small bioload in that tank is what is contributing to the low ammonia and nitrite readings. 5 tiny fish in a 20 gallon tank is nothing in my opinion. Both guppies and neons are very low waste producers in all senses of the word. I have no idea if cylce does anything or not though.

Matt

I'd love a butterfly, but I think i'd be a pricey meal for someone in my tank. Evry thing I know is from experience. before I found this site, a cycle was an empty run for a few days then add guppies and make sure they don't die. Our tap water quality is great in Lake Tahoe, CA & we've yet to have a fish die from anything but being eaten.