[Myka]

I didn't read everyone else's replies (too many), but how big are these Butterflies Tony? I'm not sure 20 gallons is big enough...

Personally, I don't use copper on any fish. I will use Formalin before copper. At least Formalin will treat a wider variety of disease (including Ich if you really want), and Formalin is only a dip. That said, I don't use either treatment for Ich. I use hyposalinity. Butterflies are sensitive to pretty much anything, but hyposalinity is easier to turn around than copper treatment.

If you are worried about the AquaClear intake put a sponge over it. Imo, the AquaClear power filter is the best and easiest option to use on a QT.

I recently described my general QT procedures on a different thread. Here's a copy n paste (with some editing for you).

Equipment:
~ Tank
~ Heater
~ Powerhead
~ AquaClear power filter
~ PVC pipes
~ Carbon
~ Seachem Prime
~ Seachem Ammonia Alert; and/or
~ Salicylate ammonia test kit (API is preferred, Elos and Salifert not compatible with Prime)


Use water from the display tank to fill up the quarantine tank (doesn't matter if the water is infected because apparently so is the fish, right? hehe). The filter floss media I use in the sump in my display tank fits into the AquaClear with a bit of trimming. I use the used media from the display tank to "seed" nitrifying bacteria to the QT. Use two pieces of media, one new one and one used one. Once a week replace the older one with a new piece. When used water and used media are used to seed a QT fish can be placed into the tank as soon as you're sure the temperature is correct and stable.

If medications are being used I will dose the QT with Prime. Most medications will kill nitrifying bacteria so the seeded media is a moot point in the power filter - just use new media.

For Ich I don't medicate, I use hyposalinity so a refractometer is required. Google "marine ich hyposalinity" for more info on that.

The Prime is to de-toxify ammonia. The Ammonia Alert is to indicate if you need to add more Prime (or do a water change) to lower the ammonia. Ammonia is your biggest concern in a QT, and is why a person would be concerned about nitrifying bacteria. No nitrifying bacteria (due to "freshness" of tank or because of medications) and ammonia will be soon to come. You need to use a salicylate test kit to test for ammonia as the Nessler types will give you a "false" ammonia reading when using Prime. I like to use the Ammonia Alert (which I find is surprisingly accurate) in addition to daily testing for ammonia. Ammonia is so deadly and kills so quickly that it is very much worth the double check.

Use carbon in the power filter to remove medications when finished so you can monitor the fish's health post-medication for a week or two sans medication before re-introducing to display.

For Ich, I use the typical 6 week hyposalinity treatment.