# Film on water surface



## nightwing (Jul 18, 2006)

I have film on the surface of the water. I use a lily pipe return, and pressurized CO2. Is this something i need to deal with or should i just let it be?


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## mistergreen (Mar 3, 2007)

Gourami & livebearers will eat it. You can also use mechanical skimmer to get rid of it. It does slow down gas exchange so it's better to get rid of it.


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## nightwing (Jul 18, 2006)

Does everyone have this issue? Is this abnormal?


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## mistergreen (Mar 3, 2007)

It's part of the process, at one point or another.


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## EdWiser (Apr 16, 2018)

You could always use this.

https://www.eheim.com/en_GB/products/accessories/cleaning/surface_skimmer_skim350


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## dwalstad (Apr 14, 2006)

If you have fish in the tank, I would remove it. A thick film like this can block oxygen entry.

More importantly, though, it may be filled with environmental mycobacteria that can cause Mycobacteriosis ("Fish TB"). These common bacteria are oily and tend to gather at the water surface. My website contains a thorough, downloadable article about Mycobacteriosis.

When a film like this appears, I just take a cup and scoop it out. Wipe the outside of cup in between scoops, because the film will stick to the cup.


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## nightwing (Jul 18, 2006)

Thanks for the helpful like to your article, Diana. In previous planted tanks, i didnt have the surface scum phenomenon. So i am puzzled why i have it now. I have 2 pieces of wood in there that could be shedding pollutants i suppose. I recently tore everything down and restarted due to unsolvable algae issues that were driving me nuts. So now its all new flourite, 2 chunks of wood, and new plants. Tank was disinfected with bleach for a few days before rebuilding. Only fish in there are otos atm.


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## dwalstad (Apr 14, 2006)

I would agree with you that the driftwood is leaching nutrients into the water. The film is a little ecosystem of bacteria and other microorganisms feeding off of those nutrients.

For years, I have heard so many instances of driftwood rotting and causing problems. Rocks which are inert (don't release organic compounds), IMHO, are a much better choice for planted aquaria. I'm not saying don't use driftwood, just that it is organic in nature, and because of that, it can cause problems.


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## Cavan Allen (Jul 22, 2004)

IMO, removing the surface scum is a virtually a REQUIREMENT. As mentioned already, it inhibits gas exchange. That's a problem for your filter bacteria and everything else. If you're adding co2, it can trap excess. I now use the Eheim Skim 350 and though I have to clean it weekly, I like it a lot.


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## Gerald (Mar 24, 2008)

Wood, tree leaves, and fish food are potential sources of oily film. I use paper towels to remove it. Lay the paper towel across one end of the tank and drag it across the surface toward the other end. Have a bucket or plastic shoebox waiting to drop it into.


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## Cavan Allen (Jul 22, 2004)

Gerald said:


> Wood, tree leaves, and fish food are potential sources of oily film. I use paper towels to remove it. Lay the paper towel across one end of the tank and drag it across the surface toward the other end. Have a bucket or plastic shoebox waiting to drop it into.


I think that's a fleeting solution though, and not as good as something to deal with it consistently and prevent it from accumulating in the first place.


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## Gerald (Mar 24, 2008)

Cavan Allen said:


> I think that's a fleeting solution though, and not as good as something to deal with it consistently and prevent it from accumulating in the first place.


Very true, but "fleeting solutions" can be useful in emergencies, like a power outage.
... and its so satisfying to watch it all disappear in 3 seconds.


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## Michael (Jul 20, 2010)

Cavan Allen said:


> IMO, removing the surface scum is a virtually a REQUIREMENT. As mentioned already, it inhibits gas exchange. That's a problem for your filter bacteria and everything else. If you're adding co2, it can trap excess. I now use the Eheim Skim 350 and though I have to clean it weekly, I like it a lot.


The Eheim is my favorite method too, and it will also clear a tank of duckweed!


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## nightwing (Jul 18, 2006)

I removed the wood today to see if that reduces the film buildup. I’ll post again in a few days and let you know. Thanks for everyone’s comments!


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## nightwing (Jul 18, 2006)

The problem of scum building up on the water surface has been greatly reduced by removing the wood, although the aquascaping doesn't look nearly as nice now. 

Another problem has cropped up, which I'll ask about in a separate post. 

Thanks everyone!


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## Yorkie (Sep 8, 2014)

EdWiser said:


> You could always use this.
> 
> https://www.eheim.com/en_GB/products/accessories/cleaning/surface_skimmer_skim350


I have a skim350 and it poses a serious risk to fish and shrimps. Within a few hours' use, one of my Corydoras habrosus got sucked into it. I made a guard that prevents this happening. But, on a positive note, the skim350 can do an effective job, albeit fiddly to optimize the flow.

BTW, your name is familiar - UKAPS, perhaps?


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## EdWiser (Apr 16, 2018)

Yes I am on there too.  
I have the ADA Vuppa which uses a sponge and float switch to keep shrimp and small
Fish out of the skimmer.


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## Yorkie (Sep 8, 2014)

EdWiser said:


> Yes I am on there too.
> I have the ADA Vuppa which uses a sponge and float switch to keep shrimp and small
> Fish out of the skimmer.


Thanks for your reply.


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## couesfanatic (Aug 27, 2010)

Try using hydrogen peroxide in a spray bottle. Spray it on the surface and let it sit. Works very well


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## Hank Junior (Oct 1, 2020)

I second the Eheim surface Skim 350 comments. For me its like the ipad. My life before the Eheim 350 and my life after. I would never set up a tank without one, its that good. Best invention past few years imo. The attachment rattles a bit, but I only run it once or twice a day to clear the surface, so its no bother. I have small tanks with it as the only filter, so I sometimes run it without the top section to just clear the water and get some water movement - but have no fish in the tank, only plants. For a fish aquarium you need the top section fitted or you would suck in fish. Its great. Trust me after using one you won't be able to live without it. The only annoying bit is the rattle - that makes more noise than the pump and filter, but its a minor complaint.


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## ethermion (Feb 28, 2012)

+1 (another one) on the Eheim Skim 350. Like they teach every young man in shop class, use "proper tools". Skim 350 is a seriously proper tool.

Another +1 to you don't have to run it 7x24.

You can also stuff some poly fill in there and push it down a bit (the skimmer) for some quick and easy mechanical cleanup.


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