Film on water surface...

Octoberfest

New member
OK I've been in this hobby for over 10 years and this one has me baffled. Right now I have a film on the surface of my water and everything that I can think of tells me I shouldn't.

The tank has a footprint of 66"X33" including a coast to coast overflow with two 1.5" drains on durso pipes. The return pump is a Mag18 running wide open.

I swear my water level in the overflow was lower but now the elbows on the durso area about 85% covered with only the tops showing.

I have holes drilled in the top of the dursos and to ensure they weren't too restrictive I even took the tops off, while very noisy it didn't change the height of the water in the overflow.

The ONLY thing that has been changed on this tank is I went from Metal Haldies to AI SOL led's. Is it possible that I just never noticed this film? If so...any ideas on how to fix it?

I feel like this is a rookie issue but it has me stumped.
 

Agu

Premium Member
Changing the lights won't change the water level. I'd check for restrictions in the drains. Is the water level in the overflow almost as high as in the tank? If the water level in the overflow rose enough you'd get less surface skimming of the main tank.

My guess is that a snail or something else is partially blocking one of the drain lines. I once had the same problem with surface skimming and it was due to valonia growing in and restricting the drain line.
 

Octoberfest

New member
Changing the lights won't change the water level. I'd check for restrictions in the drains. Is the water level in the overflow almost as high as in the tank? If the water level in the overflow rose enough you'd get less surface skimming of the main tank.

My guess is that a snail or something else is partially blocking one of the drain lines. I once had the same problem with surface skimming and it was due to valonia growing in and restricting the drain line.

Hahah yeah I meant that because I changed my lights maybe that's the only way I noticed the film, not sure if that makes sense.

As far as snails go there is no way for a snail to get to the overflow. I know that may sound crazy but the way the stand is setup it cuts off the main tank from the overflow. Also I've only had small trochus, nassarius, and cerith snails in this tank, none would be big enough to clog it. I may still try and run something through the plumbing though.

Right now the water level in the overflow is about 1" lower than the main tank, so it's still moving pretty good.
 

reeftivo

Skim junkie
I had a decrease in my return a while back and started developing a film on my 90 (single 1000 gph overflow) and found that my overflow PVC was loaded with vermetid's (tiny tube worms). I mean loaded with them! I had to actually replace the pvc because it was easier than scraping them out.
 

aleonn

New member
If there isn't enough agitation of the water surface, an oily film may develop. Maybe try pointing a powerhead towards the water surface to see if it helps.
 

Octoberfest

New member
If there isn't enough agitation of the water surface, an oily film may develop. Maybe try pointing a powerhead towards the water surface to see if it helps.

Because there is a coast to coast overflow it should rip the water surface right off. I also am running a closed loop through a Reeflo Dart but there is a bunch of surface agitation going on.
 
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