Oxygen diffusion into water

[moldyform]

To get adequet oxygen diffusion inot the water should lids be left off the tank?

Cheers

[ILLUSN]

Not really, lids arn't airtight, so even closed air still get in also you have thermal currents caused by the air under your lids heating up from the light and tank, and rising, as a result more air is drawn in.

most air diffuses in from the surface of the water so if you want to increase O2 in your tank get more surface movement going.

if full blown planted tanks its not unusuall for plant to super saturate the water with O2 during "light on" hours, in such tanks surface aggitiation isn't needed, only at night when the plants consume O2.

[moldyform]

Also, is o2 diffusion restricted by a film of float floating alge that i constantly have?

Cheers

[ILLUSN]

I dont think it will help your situation LOL, maybe concider adding a skinner to your filter, like an eheim skimmer or something like what ships with the aquis 2200 and 2400 filter, it will remove it for you for good.

[moldyform]

did you mean a skimmer? Only way i can see of getting rid of it is wit hsome form of surface skimming set up.

I physically remove the algae film and with in a week or two its back with vengence. It becomes a pain to do tank maintance as your arm becomes covered with it after any work.

Cheers