I’d like to expand upon @Discusluv
I agree about waiting until further evidence appears. However, I would always want to have on-hand some medication for this. I keep Seachem’s Paraguard for this and other targeted parasites. It is a good general-purpose medication.
If you do decide to treat, recognize that Ich has three stages and you can only kill it in one of those three stages. These are, in non-scientific terms:
- On/in the fish with white spots showing: can’t be treated. Best to hope for healthy fish to survive it and do what you can to minimize stress.
- Fall off the fish and lay on the ground incubating: can’t be treated.
- Hatch and start swimming to find a new fish to attack: this is the only point that the medicine works.
The whole process takes about a week. So, you usually want to continue treatment for at least two weeks after you see the last spot disappear.
Old wives tales:
- Salt kills ich: it can to some degree, but it dramatically increases the stress on some fish (osmotic pressure issues), making them weaker and is unnecessary given the medication available now.
- High temperatures kill ich: nope, it just speeds the cycle and, hopefully, the fish will survive a little easier but, again, the medications at current temperatures are a better approach.