QT Cleanup

[badfish]

My yelllow tang has been in QT for observation for alomost a week now. It is a 20 Gallon tank and is now housing just the small tang. I noticed the bottom is starting to get a little dirty. Any ideas on how to clean this up, i dont have a vacum. Also how often should i change water, do you think 1 gallon a day would be good enough to keep my levels in check?

Thanks.

- Jeff