Equipment & Supplies • FILM

[mpoland33]

I have had a canister filter running for about a week. First one I've own. Before, I've always had a HOB. The water is perfectly clear but when I open the canopy to feed there is a type of film on the top of the water. Its almost like an oil slick but just on the top of the water. It's been the input and output. I'm assuming this is not norma?

[cichlid-gal]

Its called a bio-film...here's some info on it http://theaquariumwiki.com/Bio-film . You probably need more surface movement. There are a couple of ways to achieve that.

You don't say what canister filter you are running but one option would be to point your canister outtake towards the top of the tank rather than straight out or down, this will cause the surface of your water to move and allow the film to broken up so it can be removed by the filter. Another option would be to attach a spraybar to your canister outtake. Many on this forum have done that and are very happy with the results. Another option is to run one or more airstones in your tank. These will help break up the surface water providing better oxygenation.

Possibly others have so additional suggestions. Good luck

[748johnd]

It is pretty normal and more than likely caused from fish food. The best way to get rid of it is to use a surface (not protein) skimmer and they only cost around $10. Fluval, AquaClear and Tom's make them and they are all basically the same and can be hooked up to a canister or HOB filter. They come with adapters to fit most filters. I prefer using a separate filter hooked up to a surface skimmer just to do the surface skimming. I keep my main filter just for regular filtering. Some advocate agitating the water surface, but this only breaks up the film and if you stop the agitation the film will be back. Drs. Foster & Smith sell a HOB filter with a surface skimmer attached. It is called the Bio System Power Filter & Oxy Surface Skimmer. If you decide to go that route you would have to call them to find out which of the five models would fit over the rim of your tank. If it is a 55 or larger you would probably need the largest one. Eheim makes a surface extractor, but it is quite expensive. Hope this helps.

[mpoland33]

cool thanks guys

[Mike_G]

Some advocate agitating the water surface, but this only breaks up the film and if you stop the agitation the film will be back.

That's true. I just turn off all the filters and then draw the film off the surface by immersing a 1qt. Snapple bottle and letting the surface layer slowly drain into the neck of the bottle. Then it's out of the tank rather than just broken up and suspended. NLS is pretty oily.

[Dawg2012]

That's true. I just turn off all the filters and then draw the film off the surface by immersing a 1qt. Snapple bottle and letting the surface layer slowly drain into the neck of the bottle. Then it's out of the tank rather than just broken up and suspended. NLS is pretty oily.

Interesting... How long does it stay gone for?

[748johnd]

It doesn't stay gone for long. I used to let it drain into a container and I've used paper towels. You set the towels on the water surface and they will pick up a lot of the film, but it will be back soon. Using surface skimmers gets rid of it. Again, if you stop using the skimmer it will be back soon, just not as soon. My experience is that most of the film is caused by the fish food. By using skimmers my water surface is always free of film.

[13razorbackfan]

It doesn't stay gone for long. I used to let it drain into a container and I've used paper towels. You set the towels on the water surface and they will pick up a lot of the film, but it will be back soon. Using surface skimmers gets rid of it. Again, if you stop using the skimmer it will be back soon, just not as soon. My experience is that most of the film is caused by the fish food. By using skimmers my water surface is always free of film.

This is true. I used to do the same thing with paper towels and agree that it is probably the oils in the foods. I still get a film on top when I shut off my spray bar. The spray bar breaks it up and allows it to be filtered just not as directly or effectively as a skimmer. It would clear up after 48hrs from last feeding but I feed every day so it will always come back.

[decepticonpaul]

i had that when i just bought my canister filter. after about a week it was filtered out of the tank by itself. looked like greasy oil floating on the surface. my guess its from the new filter parts.