I have a 6ft high 150 gal cylinder artificial reef tank that filters to a live rock sump in my basement. I also have a reef octopus skimmer in the sump. The tank has good circulation but the water on the very top is very slimey/bubbly, in fact its almost like oily spots in the water. What can I do for this? Do I need a powerhead on the top of the tank or is there something I can add to the tank (chemical or fish/inverts) to help.
thanks
thanks