Hello all! This is my first post...I've been having a lot of problems figuring out what is going on (lots of Googling and forum searching to no avail) and hoping that someone here can provide some insights.
I have 2 spotted puffer fish -- in 30 gal bowfront tanks (seperate). Have had them since October 2022. One is thriving, the other is turning black. I assumed it was a parameter issue, but that doesn't seem to be the case. Parameters are:
Temp = 80-81F
GH = 180 mg/L
KH = 0-40 mg/L
pH = 7.5-8.0
NO2 = 0
NO3 = 0
Ammonia = 0
Hydrometer Reading = 1.009
Feeding a combo of frozen shrimp and bloodworms, and live ghost shrimp and snails. Feeding every other day.
Water changes are weekly with about 25-50% water changed. Water conditioned with Prime.
The only thing I can think of is parasites, but I'm not sure what it would be or what to treat with. No white spots present, and belly looks skinny not distended. Puffer is eating, though I would say not as much as the other one who is normal coloration and swimming around. Mostly it hangs out either resting in a cave or on a rock, but will swim around (just again, not as active as my other one). At this point, the puffer is fully black, you cannot see any spots, and has been like this for a few weeks as I've tried to figure out what is going on.
Any thoughts or suggestions would be appreciated!