Hi, having an issue with one of my marble mollies. He was fine yesterday and then today he seems to be having trouble swimming and spends all of his time sitting on the tank decorations (not sure if that counts as bottom sitting because he's not going to the bottom of the tank to sit on the sand, he's sitting on the rocks or the plants at about the mid-level of the tank). He still seems interested in food but swimming is obviously hard for him (he wiggles his head way more than he needs to, so it looks like he's swimming in a really exaggerated way) and if there's not food to be had, he doesn't move around much, just stays sitting on the rocks.
No ich, no velvet, no mites, no excess slime, his eyes don't look cloudy, his fins aren't clamped, he's not pineconing, and he doesn't seem bloated.
I have no idea what's wrong or IF anything is wrong. None of my other fish are acting weird right now, just the one molly.
29 gallon, partially planted, sand substrate on top of gravel, Penguin Bio Wheel 200 HOB
filter. Cycled for 6 weeks, fishless. Fish added ~3 weeks ago.
3 black mollies, 1 angelfish, 2 marble mollies (and 1 teeny fry that has managed to avoid being eaten by the angelfish), 1 bristlenose pleco (currently ~2 inches long).
Temp 79F, pH 8, GH
Last water change was 20% done 2 days ago.
I know my nitrates are a bit high, I'm in the process of trying to get them down with PWC
. And I don't have an ammonia test kit right now but the last time I checked (a couple weeks ago, just before I got my fish), it was at zero. It's entirely possible it's changed but I don't have a way to test it until I get paid again next week.