Today I noticed Omelette has a slit in his "belly fin" (I don't know what it's called!)... As far as I'm concerned, the water quality isn't bad. I change 40% of the water every 3-4 days. The last time I changed it was on Saturday. The water quality is alright (I only have an ammonia test kit...the ammonia is at 0), and there is very little algae growing in the tank, which I'm assuming means the nitrates are low (?). Right now there's plenty of anacharis in the tank. There's also a silk plant, and 2 other fake plastic plants.
The plants sticking out of the mug handle seem a bit rough (not sharp though) so it might've caused a split in the fin. Unless I have bad water quality and I don't know
But yes, I just noticed it today.
Should I quarantine him? The salt used to heal the rip would probably hurt the plants and the ghost shrimp tankmate, right?
That was the clearest picture I could get because Omelette was very excited (it was easier to see when he was flaring) and was moving around a lot. Also there was very low light.