Definitely do as the princess says, get yourself a treatment asap! Provided you treat quickly your fish should be OK.
Also, make sure when you treat the tank that you remove any carbon filter if you have it. Raising the temperature in your tank to about 82ºF (maximum) will speed up the life cycle of the parasite and hopefully mean the treatment works quicker too. Make sure you increase the temp gradually though, you don't want to stress them out!
How long have you had your fishies? Ich is often common in new tanks and can be a sign that the water conditions aren't great. So if you haven't done so, do a water change asap. If you already have your ich treatment, just add the correct amount of dosage to the new water you're adding, and then the treatment won't get diluted (hope that made sense!).
Hmmm what else is good to know about ich... oh yeh, contrary to what the medication says, it's best to continue the treatement
every day until all the white spots have
completely disappeared. Otherwise it might pop up again a few weeks later which would be bad news
.
OK that's all I can think of! There is an article
here about the disease which is really helpful
- good luck!