Film on Top of Water

[davidandpam]

In my 120gal established tank with lots of live rock, tank, clown, flame angel and anemia, snaols, crabsshrimp, star fish etc I am finding a skim brownish color on the top of the water. I have a pleunm system with a good protein skimmer on the tank. I am having some problem with a browinsh fur like buildup of algie on the rocks as well. Using 400 watts for metalhalide lighting. Any suggestions on how to lessen algae and remove skim. I use R/O water and have four pumps for circulation. David

 

[thomas712]

Sounds like you have a buildup of dissolved orgainics. In order to break that up you have to have surface agitation, this can be accomplished by powerheads.
One of the best ways to avoid this is by having a surface skimmer or overflow system that leads to a sump underneath the tank.
Thomas

 

[sammiefish]

One additional way to remove dissolved organics it to use carbon somewhere in your filtration system. This can help however I think thomas mentioned the best primary defense/fix.

 

[xnikki118x]

Thomas and sammie gave the best suggestions, but there's also a simple way to agitate the surface of your water. Just add a bubble disc/bubble strip/air stone. It easily hooks up from an aerator through small standard airline tubing, and it adds a little more activity in your tank, too. My crabs like to hang out right where the bubbles come up from my crushed coral, and my oscillaris likes to swim in the bubbles.

 

[davidandpam]

I pointed one of the powerheads toward the surface and it now produces a continuous bubbling sound with a clear water surface. Thanks for the suggestions.