a clear film present on the surface of the water

[Bravofleet4]

Hello,

I've recently noticed that there's a very thin clear film on top of the surface of the water in my fish tank. Based on just that description, it wouldn't bother me that much but it looks sort of like a plastic skin when a bubble is trapped underneath it. It doesn't pop either but feels like a membrane between my fingers. What is this stuff? Is it a sign that I'm not changing my water enough?

Thanks

[Lupin]

Could be oil from fish food which can disappear from sight through surface agitation.

[ct-death]

How much water conditioner did you use on your last WC? Did this occur recently after a WC?

[Cyberpaddy66]

What is your tank set-up, do you have any air stones or trickle filters?

I had a film on top of the water in my kitchen tank, shortening the down pipe on the hood filter so that water falls into the tank got rid of it in under an hour :D

[Bravofleet4]

I use the recommended amount of water conditioner which is 0.5 ml per gallon to neutralize chlorine and chloramines. I have to emphasize that it's only present on the very surface of the water meaning that if I skim the top off it's completely clear. That said it's also kind of gross because at some points it looks like a skin peeling off the water.

[jrh]

People have talked about these before as being caused by dissolved organics in the water. You can take it off with a paper towel. Agitating the surface (ie, pointing the water return towards the top or adding an airstone) should help, and some fish like mollies will actually eat the stuff.

[PufferFan]

my tanks went threw a fase like this i payed no atintion to it and stired up the water every now and then ... the odd thing is it quit. i didnt change anything water levels are the same filters same yet the film is gone... i think it was just the quality of the air or something idk

["13"]

surface agitation is key to clearing this and promoting better oxygen exchange.

[Bravofleet4]

okay thanks maybe i'll try getting a more powerful filter

[andi872]

i have a simlar situation did not think any thing of it till now, mine just looks like a oily film, but i have quite a bit of surface agitation

[Star_Rider]

as mentioned..it is most likely due to dissolved organics..in marine tanks a skimmer foams the stuff and clears it.
they now make surfacre skimmers for some filters.the allows the stuff to run thru the filter and be removed mechanically.

the surface skimmer works like a small overflow.