Stubborn Protein Film
 

So my tank has been going along fairly well lately, but one thing I can not seem to fix is a fairly thick protein film on the top of my 30g. I do 20% water changes every 2 weeks, my skimmer is skimming about a half a cup a week and i have one koralia nano powerhead running 9 hours a day along with the 205 canister. I know thats not a lot of flow but every time I try and add more, like another nano skimmer, or even a 750gph fish panick, all my corals (all lps) close up. Ive tried removing it manually with the net and it only goes away for a few hours. I would love to find a way to get rid of this..:biggrin:

I don't know if this is your problem but I will describe my surface film problem and how I solved it.

The toothed overflow gate where the water exits the main display had "teeth" that were too long and as a consequence the water did not flow out via the surface of the display but just under it. The solution was to block off the lower half of the teeth with some flat plastic from a CD case which forced the water to truly leave the display from the surface. Beware this will raise the water level in your display.

I'm assuming you don't have a sump....

Sump or not...the problem is that the surface of the water needs to be drawn into the filter somehow. If that is impossible, aim a pump at the surface to agitate the surface and mix those organics back into the water.

You could try the fluval surface skimmer attachment. I've used it for freshwater. It does what it is ment to do, skim the surface.

Thank you for the feedback guys. I dont have have a sump, but i might be able to get the intake on my pump aimed at the surface somehow... also the suface skimmer is a good idea, any other ideas?

thats what my moneys on:)

When I had my 90 gallon going, I attached a Tom Aquatics Aquarium Surface Skimmer to my filtration. Works really well once you get it tuned in.

Going back to what Snaz had to say, how does the water enter your current skimmer ?
Looking into what he did for his tank may be the direction you need to go with your current skimmer intake

You could add a surface skimming attachment to your skimmer or filter.

Once you solve the surface film problem, I strongly suggest you cut back on the tanks lighting schedule or you may burn some coral. I added a sump to my set up last year and lost a few corals since the surface film was quickly removed, causing light intensity under the water to suddenly increase.