bob965;3731194; said:You say you don't use dechlorinator, and your city recently had a boil water advisory. It is possible that your city increased their chlorine concentration as a precaution, and this is the reason your fish are showing distress.
If your city treats the water with chlorine/chloramine, you should be using a dechlorinator with every water change. There's no reason not to. A lot of fish can probably survive water changes with chlorinated water, but that doesn't mean that it's not doing long-term damage.
I would agree with this. The city water might have bumped up its chlorine.
Also, fish flash from high nitrates, ich, gill flukes, etc. Sometimes its just random, other times its a problem. I have seen my fish do it to get poo off as well.
If it seems random, I'd just keep an eye on things, if it seems to be constant, I'd keep a closer eye on things and try to narrow the problems.
At this point though, I'd say some Prime couldn't hurt things.