after going through 3 schools of 4 barbs/silver dollars in a week trying to cycle my 55gal tank, i decided to get a pair of juv. giant black gourami's. the pair survived my entire 5 week cycle process. they made it thru all the PH changes, nitrate/trite spikes, and bio load cycles, with apperantly no ill effects. not sure if it has anything to do with their labryinth organ, but these are diffenatily my choice for cycling a new tank/canister filter without using any chemicals (aside from water conditioner).
lol cant edit my post now -so just disregard