in my 55gallon, up for about a year...using a HOB red sea prism skimmer. When you look at the tank from the bottom to the top of the water. the water looks like it's oily. or there are thing floating at the water. what can i do to get rid of this. iv done water changes. its not oil though..............also there are alot of little bubbles all of my rocks too... when you touch them.. they go to the top and dissappear. any help?