QT water change

[mhurley]

So, my QT is about 40 gallons with only a Red Sea Berlin skimmer in it. How often should I do a water change?

My display tank has been runing for 5 years, no ick...I'm more worried about the new fish bringing the ick to the tank, not the other way around. Sooooo....can I take water from the display and use it for a change to the QT? The display water is skimmed far better than the QT is so it should be fine to use from that standpoint.
I'm not that lazy (well...maybe), just trying to save some steps if possible.

Thoughts?

[ralphie16]

that is exactly what I do. I have a 10 gallon isolation tank. Here is how I do it.

I take 3 gallons from the hospital tank and pour down drain. I take 3 gallons from my main tank and pour it in the hospital tank. I take new saltwater and pour it in the main tank.

This also is great because the new fish will adapt to the water conditions that it will eventually be living in.