Hello, one thing that keeps nagging at me is the use of the Microbe lift. I went to their site and unless I'm missing something all their products relate to ponds. This may or may not be anything to be concerned about but could you tell me the exact product you are using? There is no such thing as over filtering to respond to your question concerning that. The skimmer is fine, it should only accumulate 1/4-1/2 a cup from a dry foam set up and it shows the tank is healthy with no over producing of skim. I would stop using (stop doing) what you are doing now i.e. the Microbe lift and purple up only because it is not giving you the desired outcome. Use another source of calc and mag. Pictures would help a lot. The proper Iodine level (in sea water) is .06 with .08-.09 becoming lethal so you are on shaky ground there. Stopping the purple up will assist in the depletion of the excess Iodine. Post pics if you can.