Yes! When the white spots disappear it does not mean your fish is cured. What it does mean is that the parasites have left the fish's body and are down in the substrate multiplying and then they'll swim back up to look for another host...reinfecting your fish. Now, when the spots have disappeared, is the best time to medicate...it's your real window of opportunity to kill all the little buggers.
So keep medicating as directed my your medication instructions (I used Cure Ick for a little over a week--three separate dosage periods--on my Solomon and he's all cured. I now use Aquarisol once a week, with one of his water changes, as a preventative. I use it with Samson too...he's never had ich).
