biological filtration

[WorldNation]

how exactly do i start up a biological culture in my tank? i have an AC 500 and a Penguin 550 PH in the tank, if i add a sponge to the PH, will that help? also, how do i keep it alive if i do constant water changes and clean the filtration units? wont that kill the bacteria or is that fine?

[SGypsyMermaid]

here are several threads which deal with the nitrogen cycle:

http://www.cichlidforums.com/search.php?mode=results