It is a protein build-up. It comes from the food, and from the fish. It is
normal. A little surface agitation will suspend it in solution for
filtration. People who use hob filters like aquaclear do not see this
because the filter agitates the surface. If you do not want to agitate
(due, lets say to plants needing the extra CO2) you can float a single sheet
of newspaper or even a paper towel for just 30 seconds or so, and it will
absorb the layer. When I do my water changes with the python system, I
invert the nozzle and "slurp" the water from the surface. This skims it off
nicely.


"Troy Bruder" wrote in message
...
That's EXACTLY what I'm seeing!


"Nikki Casali" wrote in message
...
I seem to have a similar film or scum across one of my planted tanks.
There isn't much movement at the surface. That's good as I don't want the
CO2 to dissipate too easily. But a scum builds up. I think algae even use
the scum to their advantage by hanging on to it and bathing in the light.
It does block a little light.

I have only been feeding my fish once a day, and only with sinking
tablets. The irony is that today I dropped in a few flakes and the scum
scattered in every direction, clearing it away to the sides. I'll try
feeding more often with flakes, I think.

Nikki

Shagster wrote:

My last water change was within 5 days... Plus, I'm only feeding my
fish 1-2x per week, so I don't think it's that... I'll increase my
water change frequency and see what happens.

Thanks!
Troy



"Happy'Cam'per" wrote in message
...

Could be from protein build up in the water, when last did you do a
water
change?
If not the water change it could just be residue from the fishfood. I've
heard that certain dechlorinaters can also leave this oily film. I
would'nt
worry too much about it though, as long as you're doing weekly water
changes
I think you'll be ok.
--
Kind Regards
Cameron


"Shagster" wrote in message
...

Hello,

I have a new problem I'm hoping someone can help me with. I have a
moderately planted 30 gallon tank.. The water is crystal clear and all
of
my measurables appear to be in check...

Here's the odd thing.. When I come home, and look into the tank.. At
the
top of the water are thousands of tiny "trapped" bubbles from the
photosynthesis during the day than cannot escape. If I put my hands in

the

water, there appears to be a slimy film on the top of the water that's
preventing the bubbles from escaping.. If I stir the water, I can see
the
film "gooping" up into white chunks and floating around..

Any idea what that's all about?

Thanks,
Troy