Recently I have been getting bubbles on all my corals and I can't figure out why. I'm having a bit of trouble getting my skimmer setup again after running medication and having to turn it off as I can't get the air valve fully open so I'm getting a lot of micro bubbles in the sump but not loads in the display tank but the big bubbles on everything I can't work out so any ideas would be appreciated.
Pictures below as they don't seem to be causing any problems at the moment but don't want them as a permanent fixture in there.