film on water surface

so I have some good news...

If you look at the sketch I made, you'll see what my overflow looked like (#1) and what it looks like now (#2)

When I setup the overflow, I was told to add the elbow, to make everythin run more quiet. Looking at the film, and where the water level is, it only makes sense that the film doesn't get sucked into the overflow, as the entrance of the overflow is underwater.

I removed that elbow piece (as seen in # 2), and the water gets sucked into the overflow, breaking the surface. Within 30 seconds, that film of gunk (that I'm figuring has been that way since I setup the tank last year) got sucked into the overflow and completely disappeared.


Fortunately, I didn't have to move the powerheads. I checked out the flow, between the PH and the sump return, and there's lots of water surface movement which all leads to the overflow.


Thanks for noticing, Ace... had you not mentioned anything, who knows how bad this could have gotten.


thanks for everyone's advice.

internal overflow.jpg
 
You didn't actually have to get rid of the elbow. Shortening the standpipe would have allowed for a large enough height difference to help in "pulling" the protein/lipid film off the surface and into the overflow. If the water level is too high, you won't get enough movement of the surface tension to get it flowing. It is literally a floating layer of hydrophobic molecules--like another little "ocean" on top of the water's surface. You shorten it enough to make a slight fall, but not enough to make much, if any, noise.
 
Not necessarily. What it will do is remove it from the tank surface. The film would then collect in the overflow and the turbulence of incoming water will allow it to be sucked, little by little, down the standpipe. Your way work fine, too, but I was just saying you don't have to do that.
 
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