[Nate]

Hey Apex,

I work for a distribution company that distributes hydor pumps in western canada, we have sold 2500 + pumps and have never had this issue. I would suspect you had another problem in your tank. It was likely not the pumps as I would have heard of a problem from the manufacturer as I talk to them very often.

soft corals aside, with velvet present in the system, it does not sound like it is a very healthy one. I'm sorry to hear that you suspect this is your issue, and I wish you good fishkeeping in the future!

OP,

Again I challenge you to take my suggestion from page 2 and throw the powerheads back in pointed at the surface.

Your surface "scum" is a protein layer. Protein skimmers can pull protein from the water, but many rely on aquarium overflow boxes, overflows, or powerheads to keep the protein in the water. Your skimmer will not be efficient at removing the floating protein on the top unless it has a surface extractor on it like the old hang on prizms or skilters...

I would bet that your fish look worse in the morning becasue CO2 levels go up at night naturally as photosynthesis is not happening.

Alternatively, if I cannot convice you to throw the Koralia's back in, take your average gravel vaccum, start a syphon, flip it upside down in the tank, and suck the proteins off of the waters surface. This will increase oxygen exchange and I would bet some money that that is going to show a difference in the tank, and perhaps that will convince you to throw the koralias back in.

I only hope you get to it, as when oxygen levels get too low, you wont just lose one fish. They will all die if oxygen levels are the case. Soft corals and inverts will be able to handle the lower oxygen levels (for the most part, not all), but will eventually die if this problem continues.

If you were in Calgary I would lend you two of the many koralias I have laying around so you could see for yourself.