So I got a sack-o-mollies from a good buddy last night and I'm planning on transitioning them to full salt. I know this can be done in a few hours, but that the long term survival of the quick acclimated fish isn't very good, so I'm planning on taking a week or two. I'll be doing small increasingly saline water changes each day. The tank is a standard 25g kept at 80 degrees. The tank is currently running with a fully cycled (freshwater) sponge filter, but obviously that isn't going to do much for sw biofiltration. So my 1st question is when I should start adding liverock (at what salinity level)? Or is there a better way to provide biofiltration in a 'temporary' setup like this? I have plenty of other sponge filters sitting around and a few small bioloaded sponges in other sw tanks that I could toss into a hob filter. Assuming everything goes smoothly I should have a few extras at the swap too which I'll post closer to the actual date. Edit: not 100% sure this is the right section, mods feel free to move.