parasites in hospital tank

[cooksreef]

I recently broke down my reef tank and started over but in the meantime my dory contracted ich in my ten gallon . I am now ready to put fish back in the main tank, should i treat it with formalin, I can't put it in the hospital tank because of my snails starfish and dusters

 

[karajay]

Formalin is NOT recommended, nor is it effective to treat ich.
Put the inverts back in the main tank and treat your fish in quarantine with hyposalinity.
If you are unfamiliar with the procedure, I recommend you read through the FAQ sticky in the disease forum. Lots of good info in there.
Putting a fish back into your display tank with ich will re-infest the entire tank. I recommend you quarantine every fish you intend to put back into your display to avoid future ich outbreaks.
Just out of curiosity - why did you break down your tank and start over?
:notsure:

 

[cooksreef]

I added a uv light to kill suspended algae because i couldnt control nitrate even after massive water changes, but this killed my corals instead, so i bleached all of my rock and scoured the tank leaving only the biowheel and sump water, then added all new ro di water sand and the now white rock and waited a week for skimmer to clean up any chlorine residue in the meantime 1 of 4 fish got ich i did use the formalin and a little malachite green in desperation today , the inverts didnt like it , i put i starfish back in display, maybe this wasnt a good idea either?