I am still battling the ammonia- I'm Sorry I didn't answer the posts- this site doesn't notify me when I get a reply despite the fact that the box is checked!
Skylab- I have been running my reef for 3 yrs., and this is the first time I've had a problem in the QT with ammonia. I use an Aquaclear 50 (has 2 sponges) which is good for a 20-50 gal tank (mine is 20 gal). I use the reef tank for water changes, as I feel it is more stable. When I do large water changes only from fresh mixed salt, I seem to have more alk. and ph swings. Also, this is the water he will eventually go into. I don't think of it as"old" water, but as the environement that my corals and fishes thrive and grow in.
I thought I had the prob. solved a number of days ago, as the ammonia in the water with the fresh brine being the culprit- alas that was not it. I continue to do the water changes-50%, pain in the butt, every day.