Fishless Cycle

[hemlock]

I've read different opinions.  Do you have have to add a bacteria source?  If you add the household ammonia, does the bacteria just come from the air or w/e or do you really have to add gravel or filter media from an established aquarium?

[Cholly]

It's much faster if you add a bacterial source, but it will occur without it from, as you suspected, airborne spores. It just takes longer to reach the number of bacterial organisms necessary for a complete nitrogen cycle. It's also why we recommend not adding too many fish at one time, the bacterial colony needs to increase to deal with the increased bioload.

[spudfeger]

Just to clarify- most store-bought "additives" don't work. The bacteria inside are either long-dead or inappropriate for most aquariums. I personally experimented with Seachem's "Stability" and it failed to perform as indicated. Added gravel or filter media will often cycle the tank almost instantly, as Cholly said. If you have any aquarist friends I'm sure they wouldn't mind at all to give you some. Otherwise, the cycle will take around 4-6 weeks, depending on tank conditions. Kudos for being responsible enough to cycle fishless!

[RinsMom]

Also, if you do get "filter squeezin's" or gravel from a friend, don't leave it sitting out too long... the bacteria will die without a food source.  I don't know a timeline, though.

[Santaaa]

Tetra's Safestart works I have used it to set up many tanks and have yet to get even a bad batch. It is Marineland's Biospira under a new name.