gaping polyp

I am having huge problems in my tank as of recent and am trying to figure this out and rule it out as a problem. I have a Tunze 9001 in my Waterbox Cube 20. The only way to use this skimmer is to put the skimmer facing sideways and the magnet is being submerged in the water. I was wondering if...

So I have an all coral tank as of right now and out of the blue I noticed a strange growth behind my frogspawn. I don’t know weather this is dangerous or if it is some sort of coral. It is colored purple/blue with orange dots

I've had my BioCube14 established for just over one year. I've had this duncan for almost a year and it has grown from one polyp to seven. Any ideas as to what's going on with it, now? The original polyp in the center is gaping and the center polyp tentacles are disappearing. Is this part of the...