help first fish might have marine velvet?

hi there i bought to clowns from a lfs about 40 miles away from where we lived.



and when i got home and lifted the bag out of the the carrier bag i notice one of the clowns had what looked like to white scratches on him just up from his tail and i thought great phoned shop and guy gives the old rubbish was all right when was at mine it will be just a bit stressed it should be fine

. now i have no other tank to put it into and had no other fish in tank

so i put them into my tank that was Saturday now its wed now and the fish is still ok no more white marks have appeared and there is non on the other clown . if it is some thing bad how long should it be till i notice some thing wrong ?

i am not putting anything else in my tank till i know that its ok



plus any one give me an idea what i need to set up a QT/H tank for the next time i buy some thing so i can see if anything comes on them



tia



john