New user looking for a little advice so here goes:
1 Golden white cloud is sick. not sure if male or female (suspect male). This morning was sitting at the bottom of the tank breathing hard, has since moved to the top of the tank between some plants, similar symptoms.
2 I do not know my tank parameters
3 The tank is ~4gal and has been running now for 6+ months
4 I use a deep blue biomaxx nano filter, no carbon
5 There are 4 fish in the tank, all between 0.25in and .5 in. The golden white cloud is the largest, then there are two regular white clouds, and a pigmy cory
6 I added water (tank was low from evaporation) last night, but took some out this morning when he started sitting on the bottom because I thought I might have overfilled tank and reduced the O2
content too low. I aerated the base material last week. I change water ~20-25% every other week (often due to evap).
7 I have had the fish now for over 3 months
8 I added a new plant (pigmy plant of some variety with flat leaves (see photo) can't remember name right now) last week
9 I have had no change to the fishes' diet lately and I feed them dry flake.
see attached photos for reference to poor minnow.
Any help would be appreciated, thanks!