Oil on water surface?

[Dinocine]

I always find a thin layer of oil...at least it is what it looks like to me, on the surface of the water where I keep my discus. I tried removing it everyday but it will return at the same rate. I have water change with about 30-50% daily, with tap water dechlorinated and temperature raised by adding 5-10% boilded water. The 'oil' seems drifting out from behind the heater, but I'm not sure it is the cause.

[Matt Nace]

Is your surface water still or slow moving?

not sure but I thought is was a protein buildup.
Some people have sililar propblems(if it is actually a problem) and add a surface skimmer(I think from eheim)

[arcab4]

i used a cannister filter and if i pointed it downwards, it would cause that buildup at the top. but when i slightly pointed it upwards where it causes a small ripple (but doesn't break the water) my buildup was gone.

[clothahump]

Just lay a piece of kitchen towel on the surface and remove the oil.
It is quite common in tanks that are being fed oily foods.

I sometimes see the same thing in my discus tank. Im not worried about it. Im thinking that it is most likely protein or mineral floating on the top. If you see no harm to the fish or plants, dont worry about it too much.

[colesea]

I would gently aggitate the surface of your water with small ripples and keep that layer from forming, it could block air exchange with the surface water. It is protien and oily biological build up. In the ocean, that stuff it turned into seafoam by wave action, in a river it is prevented from developing by the current action. In a tank, it should be prevented by aggitating the surface or protien skimmer.
~~Colesea

[Dinocine]

Hmm..so I should rule out that adding boiled water or the heater being the culprit. Malerubybard-I'm using an overhead filtering system with no rain pipe, therefore the water has slight current but no bubbles to encourage oxygenation. It is true that I feed the discus with frozen blood worm(contains much fat/protein ???) and beef heart. Clothahump-I'm using super absorbent sponge to do just that, but I hope to eradicate the whole problem than labouring in that way everynight and scaring the discus too often. Arcab4/Colesea-I just bought a sponge filter today, with the intention to increase the oxygen content in the tank for the benefit of my discus since they are a little quick in their breathing, and I think I'm unknowingly striking on the solution of breaking that 'oily' buildup. Thanks, you guys offer great help and information.

[Matt Nace]

Not sure what the beef haeart / discus food would do...I wish I could comment.

A water heater that has disolved solids or salts would raise the PH and the general hardness but not sure how it would create a situation like you have(which I also have now that I saw my one tank.

This tank has not too much current on the one side(front) so I just moved the canister output a tad higher and pointed across the tank different. It seams to have did the job.

I wonder if the film is just a natural buildup of organics in slow moving or still water with low surface movement.

[colesea]

The film is also created by dust.  Even though you have the tank lid closed, dust still manages to get into the tank (as it manages to get into everything<G&gt and float on the water's surface. Having surface currents force that dust to get sucked up and go bye-bye in the filter.
~~Colesea

[Matt Nace]

Must be the wife causing the film then when she was sweeping the other day.....wait till I get a hold of her.... ey*