# Film At Water Surface



## JmanoftheSouth (May 14, 2004)

Does anyone have any experience with this?

I have had planted tanks now for a few years and I always get this film at the top of the water. It has never bothered me before because I have always used planted tanks as refugiums for my piranha tanks, but as some of you know I am trying to setup somewhat of a show tank in my living room. The film covers the entire water surface and looking from the top down you can't tell there is anything, but if you look from the bottom of the tank upwards (for example from the substrate towards the light) it is a smokey colored film that isn't thick enough to be slime but it does trap small bubbles. It doesn't seem to bother anything and I know that if I raise the filter outflow and put it at water level instead of underneath the water level it will break up the film. But correct me if I'm wrong...you don't want the surface agitation because it will allow the co2 in your water to escape and raise your o2 levels in your tank.

As per my other posts my tank:
65 gallon (36x18x24)
80lbs ecocomplete substrate
wavepoint 4 bulb 39 watt t5 ho (2-6700k 2-1200k)
Eheim filter (don't remember model # but filter is up tp 90 gallon)
Pressurized Co2 ordered and in the mail. Hopefully I get it and set it up by christmas.


----------



## CLUSTER ONE (Aug 2, 2006)

It's most likely just oils from whatever your feeding them. Some fillets are alot oilier then others so try to use less oily types of fillets and it should go away. It doesn't really hurt much but it can decrease oxygen exchange a bit though i don't know if it could ever impact it a significant amount.

For fish you want as much o2 in the tank as you can. If your adding co2 for plants you dont want excessive surface movement or your co2 usage won't be very efficient as you would lose your co2 from the tank to the atmosphere which would cost you more tiem and money sicne it means your co2 tank will run out faster or your plants just don't get as much. A good diffuser is another good tool to increase the co2s efficiency.


----------

