Hi, not new to fresh water, but recently moved into a new house and finaly have room for a bigger tank. I set up a 90 gallon with a canister type filter. The aquarium shop owner suggested this for live plants vs. an over the back type filter to minimize surface water movement to cut down on oxygen transfere for the plants.

The thing is, the way I've got it set up is it has no surface movement and the surface has developed a fine scum, nearly a shimmer. Should I have some surface movement to keep it mixed so that the filter can eleminate it? Rite now I only have 16 tetra's, and a small number of plants. Will be adding more plants very soon, but didn't want to add all at once.

Opinions?

Thanks,

Will