Oily Film

[Pan]

I have a 20 Gallons tank that has developed an oily film on the surface, since this has started the water smells as well...not bad..just smells. I don't have the room for a hang on overflow for a sump and the big protein skimmers are too much for this little tank (size and cost). I am getting a new tank in a bit here then i will get the 20 drilled as well. I was looking at the fluval surface skimmer as a solution, i do water changes weekly, 15-20 % but the film comes back. is there a good qay to get rid of it...or is it something you have to live with when running a 20 gallon?

[TheReefGeek]

Increase the surface agitation by pointing some powerheads upwards to break the surface tension.

[Myanth]

I got the same on my 10 gallon nano. I just skimmed the surface with a cup to get rid of the film. Hold the whole cup under the water so just the meniscus skims in. Let it flow into the cup as little as possible. You will see the gross looking and bad smelling skim accumulating in the bottom of the cup. Don't let it overflow or you start over again. Worked for me. Helps to turn off any surface agitation a few minutes before to let the skim join together.

Good luck
Mike

[Xtasia]

Powerheads work best... but I've also heard some people on Reefcentral use saran wrap. Turn off your power heads, put a sheet on the surface then lift off, the oil should stick to the plastic. Dunno if it works, I've never tried it. Could be whoey :)

If its only for a short while I'd just use powerheads, any time longer I would just get a used prism off the Buy sell forum or ask a fellow reefer to lend me an old protein skimmer from one of their earlier systems (you know we all have it.. old stuff kicking around from when we didn't know any better.)

[hockey nut]

try using a cheap Aqua Clear hang on filter. It draws air and the surface water back down into the tank where the power heads do the rest. Worked well on my 20gal.

[Myanth]

Had a powersweep on my 10, no venturi, but still got the slime. Also penguin HOB 270 filter with no biowheel. Plenty of surface agitation... just had to manually skim. Of course.... I am a mechanic.... might be gear oil.

Mike

[SeaHorse_Fanatic]

May be from feeding PE mysis? I find that is quite fatty & sometimes leaves an "oily" film on top.

[Ruth]

I get it once in while on my 3 Nano tanks (2 X 12g 1 X 24g) On the 24 I will sometimes hook up a Remora Pro for a day or 2 to take it out. Surface agitation is a good idea but you are basically just mixing it back into the water. I do 50% water changes on my nano's once a week which seems to help.

[G1GY]

May be from feeding PE mysis? I find that is quite fatty & sometimes leaves an "oily" film on top.

I've found this also with mysis.

[Pescador]

I haven't tried Saran wrap but paper towel works great if you lay it flat on the water and pull it out right away.

[kari]

Isn't this just a normal thing that happens in all SW tanks? Some nutrients build up at the surface if they are not skimmed off by mechanical means like surface overflows. If the surface water of the tank is not drawn off or agitated enough you will get an oily film buildup whether you feed mysis or not.

[untamed]

Yes...I had this same problem on my tank. Basically, the tank itself has become a giant protein skimmer with no collection cup!

For fun, you can stick your arm straight into the middle...go past your elbow...pull your arm straight up and the gunk will coat your arm as you pull it out! Not a solution, but good to gross our your significant other!

You need to draw the water from the surface into a skimmer... or break up the surface with a PH so that a skimmer can get it later. IME, I found it nearly impossible to keep a surface feed working with my HOB skimmer...unless you have perfect evaporation control, the surface will change height and you have a lot of problems.

All that until I got a sump. That solved this problem completely as the overflow into the sump comes off the surface of the tank.

[Bob I]

The Aquaclear idea worked well for me in the past. Right now I have my Fluval return just below the water surface. It breaks up the surface tension just enough to get rid of the film. Just as an aside, in my early fresh water tanks we laid a newspaper page flat on the surface and drew it back to get rid of the film.:mrgreen: