Now I am selling my Tank (fresh water setup)

[mr_alberta]

You are moving everything from the 40 to your temporary 25 right? This is where you will be keeping the clowns temporarily right? What was the cause of your tank crash in the first place? If I were you, I'd let the rock sit in the 25 without adding any livestock of any sort in case there were/are some nasties (like parasites) still living in/on the rock. I'd just wait until you set up the 40 and cycle that before getting the clowns. That way you won't have to move fish from one place to another with will also be less stressful on them.