So things are still not back to normal.
After treating the tank with Melafix, I did a 25% water change, then 10% each day for several days.
I took the skimmer out of the tank, put it in the bathtub, and let it run with freshwater for awhile to try to remove any residual Melafix in the unit itself.
Then I had to go out of town for a few days and had to leave the skimmer off (obviously).
Yesterday I did about another 20% water change (as part of moving the rocks... more on that in the next thread).
I had four large packages of carbon situated in various positions in the sump since the initial waterchange.
And STILL the skimmer is foaming over. Ugh.
I'm beginning to think the thing is cooked. There are a stream of bubble that come up from where the tube attaches to the front. Would that have anything to do with it? Any suggestions?? I haven't been able to run the skimmer for 2wks or so. My water parameters are good, but I have been changing the water a lot.