Thin layer of oil on water surface

[spen]

I used to have a thin layer of oil on the water surface. For some other reason I did a 100% water changed without disturbing the gravel. Also clean the filter, removed all fishes and plant except CO2 on. The next afternoon I still notice this layer of oil develop. Suspect my CO2 cylinder been filled with lower grade C)2 gas.

Any advise please. Thanks

[wf7850]

Bro

u using surface skimmer??? this layer of so-called 'oil' is caused by the plants.... a surface skimmer shld do the trick....

[TanVincent]

Hi,

The thin layer of "oil" is called the biofilm or commonly known as surface scum. It is not harmful and it can be removed by using a surface extractor or dump in a few mollies

Cheers
Vincent

[spen]

I didn't use a surface skimmer. So it means not anything from the CO2 cylinder.

[lorba]

[quote:16069928aa="spen"]I didn't use a surface skimmer. So it means not anything from the CO2 cylinder.[/quote:16069928aa]

Spen, our two friends here are trying to tell you, the surface skimmer can help you remove the oil layer. A surface skimmer, connected to your external filter, will remove most stuff floating on the surface.

I am not too sure if 'lower grade' CO2 will actually condense at the water surface. Anyone?

As vincent has pointed out, the surface scum you see is usually the by product of the plants. CO2 injection or not, will not cause the oil layer. Unless you have very low ph which causes some chemical reaction on whatever things in the aquarium to release the oil, which is unlikely.

[Barbarik]

The 'oil layer' on the surface is actually excess protein given out by the plants, fishes or at times even by the fertilizer. A small amount of it does minimal harm to the tank condition. But a greater amount of its build up will reduce the amount of light to reach the bottom of the tank. It might also reduce the amount of oxygen to be induced from the air into the water.

[spen]

Points noted. Thanks everyone.

[prec]

is there any filter medium to be able to trap the protein given off by the plants? i have surface skimmer bt it seems that the layer is not going off..

[leroyfong]

does the surface skimmer need to be attached to another external filter or can they use the same external filter? I am thinking of splitting the inlet of filter to a surface skimmer. will it affect the overall suction power of the filter?

[mordrake]

i think splitting it will improve the suction power of the filter.
i might do it to mine too cos the flow seems to be slowing down...

[eriond]

just to share... i have a couple of female mollies in my 4ft and they do wonders with the biofilm. they help with the algae too.