There's no reason not to do the WC.
The
LFS might be right, then again, they might be wrong. Is there any way you can get a pic showing the spots?
Ich usually wont cycle that quickly. The spots are usually on the fish for longer before dispearing. if it IS ich, then they'll be back. If the fish seems OK and spot free, I think I'd wait to see if it comes back. How does the clown look?
