Woke up this morning to find one of my Dalmation Mollies with Pop Eye. Do I have to worry about this happening to the other fish. I read that I should do a 50% water change. But the weird thing is...This happened to the fish after I did a water change of about 30%. 1 hour after the change, I checked my parameters and found nothing to be out of whack.. 0 ammonia, 0 nititrites, 10 nitrates, stable pH of 6.8.
Should I just keep on eye on this fish or move him out of the tank? if so, what meds do i need to give him?

params are generally all good right after a major water change. Take measurements immediately before a water change, and periodically between changes. this way, you get a better idea of any possible fluctuations. for example, water may be 6.8 when changed, but go right back to 8.2 shortly after. .

"pop eye" can be many things ranging from disease to injury... we need more details.
how old is the tank?
what other fish are in the tank?
how long since the last livestock addition?
when was the last water change?
what water source was used... etc...

if you can, get a picture of the infected fish and keep us posted.

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Gold Coast Aquarium Society South Florida

the eye has healed.