An t-iasg
Aquarium Advice Addict
You are certainly not an idiot! You are very dedicated to the well-being of your fish.
Your water changes look like they are getting things back on track. It's great that the molly is doing better.
Joann has a great idea - squeeze the old cartridge onto the new to save some bacteria when you change it out. Old carbon no longer functions as it should when new, but it can become a reservoir for good bacteria. That's probably what happened in your case. It doesn't absorb ammonia either (like J. said, there's some specific ammonia-removing media for that, which a cycled tank doesn't need). The carbon cartridge with no other media for bacteria to reside is a reason I'm not fond of Eclipse filters. The bio-wheel holds bacteria, but I think a sponge-type media is better. I tried to use floss and a sponge in place of the carbon cartridge but the sponge blocked the bio-wheel flow and the floss got pulled into the bio-wheel. If you're handy, you could rig up some media in the carbon cartridge tray area. Maybe try a little pantyhose toe with bio-stars. Or just continue to use the carbon cartridge as you have been doing but try to save some of the bacteria from the old to new.
Your water changes look like they are getting things back on track. It's great that the molly is doing better.
Joann has a great idea - squeeze the old cartridge onto the new to save some bacteria when you change it out. Old carbon no longer functions as it should when new, but it can become a reservoir for good bacteria. That's probably what happened in your case. It doesn't absorb ammonia either (like J. said, there's some specific ammonia-removing media for that, which a cycled tank doesn't need). The carbon cartridge with no other media for bacteria to reside is a reason I'm not fond of Eclipse filters. The bio-wheel holds bacteria, but I think a sponge-type media is better. I tried to use floss and a sponge in place of the carbon cartridge but the sponge blocked the bio-wheel flow and the floss got pulled into the bio-wheel. If you're handy, you could rig up some media in the carbon cartridge tray area. Maybe try a little pantyhose toe with bio-stars. Or just continue to use the carbon cartridge as you have been doing but try to save some of the bacteria from the old to new.