Fishless cycle question

[friendorfoe]

Say I fishless cycle a 29 gallon tank, I finish and am ready to add my fish, I just go to the fish store buy my 15-20 various fish and plop them in? what happens to quarintine, seen as you have to put the entire bioload in at once?? What if one type of fish had contracted something in its species only tank at the pet store, then you just spread it to all of your new fish? It seems quite risky!

[JSchmidt]

Yes, you can fully stock a tank that's been fishlessly cycled (although I would hope you don't really plan to put 15-20 fish in a 29! that might be a bit much...).

You do run a risk of mixing healthy and sick fish, so the faith you have in your LFS and the quality of their stock is pretty important. With some fish that are territorial (e.g., african cichlids) the danger from adding fish incrementally is pretty high. Fish that are added first can establish territories, and new fish will likely battle them for prime spots.

I would suggest this: cycle without fish, and then add fish from a single LFS tank that make up the highest bioload. In the meantime, quarantine other fish that you plan to add, one group at a time. Odds are that your biofilter will be sufficiently robust (from the original fishless cycling) to adjust to the new additions.

HTH,
Jim

[Harlock]

Jim's idea is prudent and has value. That is a major risk of fishless cycling, as you noticed, ForF. Depending on the fish. Treating a larger tank can be expensive. For a 29 gallon, I honestly wouldn;t worry too much about it. It's only ~3 times bigger than a ten, which is my normal Q-tank, so treating it wouldn't be terrible. Unless you are looking into particularly difficult fish, I'd say adding them all at once is okay, just be prepared. Keep in mind, most any LFS you go too will have a central water circulating system, so that water is already shared by the fish if you're buying them from the same place.

[JSchmidt]

Yeah, Harlock is right. Even if an LFS doesn't have a circulating range filtration system, it is the rare LFS that sterilizes nets and other equipment that go from tank to tank.

Jim