I recently set up a 29g and used 2 established sponge filters (only 1 was hooked to airline) to cycle the tank (plus bottled bb). It's been 10 days and I added 2 pepper corys day one and 3 or 4 days later added 3 Venezuelan corys. I have 12 pygmy corys to add as well but haven't yet. I'm wondering went I should add the pygmy and if it would be safe to take out one of the sponge filters to set up my new betta tank. Thank you, any advice appreciated!