Skimmer overflowing + Coral warfare issues ???

[gregzz4]

Some more info ...

When I said it collapses, I was serious
Skimmer is currently 'bubbling' as if it was a mix of vinegar and baking soda, without the overflowing of the volcano
No foam at all, just lots of bubbling

With it's track record, if I were to turn it back up right now to get some foam, by morning it will have filled the cup, or overflowed into the sump