Betty, If This Is Ick You Should Let Your Fish Try To Fight It Off. The Starfish Is Not A Fish That Normally Will Get The Ick And Clowns Have A Real Good Defense System From This Disease. If I Was In Your Shoes I Would Have A Qt Tank Ready, And See How Your Clown Looks Later. It Is Real Important When You Set Up A Qt To Have Everything As Identical As You Can To The Main Tank, Ex. Temp, Ph, Alk, Etc. Just Use 10 Gallons Of Your Tank Water And Use It As A Quick Water Change. An Aerator Is Also Helpul In A Qt Tank, Any Extra Oxygen Intake Is Helpul. There Are Many Great Treatments For The Ick, Such As Tablets, Or Drops. One That I've Heard Works Good Is Noxich. I Have Had A Small Tang Ich Out In My Daughters 20 Gall. Tank And Her Two Clowns Gathered A Few Spots From It But After The Tang Was Out And In Qt, The Clowns Were Able To Fight It Off On Their Own. If You Do Set Up A Qt Tank Use Something From Your Main Tank To Keep The Same Bacteria And Environment, You Can Use Filter Media, Or If You Have To Even Some Of The Live Rock. If You Have To Use A Copperbased Treatment However Do Not Use Any Of The Stuff From Your Qt Tank Again In Your Main Tank, Or The Copper Can Run Right Through All Your Coral Or Coralline In Your Reef. Hope This Helps Some.
Good Luck