skimmer not foaming well after chemiclean & epoxy

[astroboy]

A month ago I used chemiclean on my tank, two doses, per instructions, 20% water change in between. A couple days later the foaming was still out of control so I did an 80% water change which helped some. I haven't had such problems with chemiclean in the past. A week after the last water change I mounted some corals with epoxy and a few days later did another 80% change. I also did charcoal for a week, changed that, then put new charcoal in a few days ago. 

 

The problem is a huge amount micro bubbles going into the tank. The skimmer doesn't really foam, just a lot of small bubbles in the water with a half inch of weak foam at the top.  

 

I've never had this problem before: after a few days and moderate water changes the skimmer foam is back to normal, for both chemiclean and epoxy. I'm really starting to wonder what the problem is. Checked the air hose to the pump, that looked fine. Has anyone had this problem? Or does anyone have an idea of what's going on?

[nburg]

Maybe with water changes that big there is nothing for the skimmer to pull out?