[NYreefNoob]

ok here is a question for some of you, ok so after 5 or 6 tanks now i have tried all kinds of flow, an article i read a year or so ago got me to thinking, i dont have much turbulance on the top of the water for 2 reasons. the high flow to me creates a ripple that would not allow light to penitrate as well, and also breaking up the nutrients as they collect to a degree at top of water, my thought as well as the other persons is, that's what the overflow is for, it's a top skim which allows it to go to the sump and be skimmed or filtered. instead of breaking it up and pushing it around the tank. with a low flow at the top would this allow the tanks filtration to work more efficiently ? yes i know the slight film, not that i can see any would partially block light, but would rather loose a little light and have better over effect on the tank. i have plenty of flow in the middle of tank and bottom so thats not concern. thoughts opinions

[georgelc86]

My outlets are positioned so that the top of the water jet hits the surrface slightly and its set a way that the ripples kinda corral the surface protiens to the overflow.

[jhale]

Rick that film will also inhibit oxygen exchange. Better to have a slight chop on the water and break up the surface film. It should not effect the light enough to make a difference.

[KathyC]

I agree with Jon.
The primary purpose of keeping the suface agitated is to allow for oxygen exchange and that is critical as we don't pump air into reef tanks except through the skimmer and that alone isn't enough.

[Deanos]

[NYreefNoob]

i do have some movement, and understand what you guys are saying, my drain has a little area between it and the sump which wuld cause a oxygen exchange as well as water falling into the overflow as well as from my skimmer. i have the hydor flows on top so it get a rotation of flow on the surface area, but isnt alot. ive seen a few tanks on here and comparing the chop of the top water of theirs compared to mine makes mine look like not much

[ILikeFish]

Interesting idea. I also be having a fan on tip could push the nutrients that away from your over flow if it was positioned in poorly. However I am sure it must also aid an gas exchange.

[KathyC]

Quote: Originally Posted by NYreefNoob i do have some movement, and understand what you guys are saying, my drain has a little area between it and the sump which wuld cause a oxygen exchange as well as water falling into the overflow as well as from my skimmer. i have the hydor flows on top so it get a rotation of flow on the surface area, but isnt alot. ive seen a few tanks on here and comparing the chop of the top water of theirs compared to mine makes mine look like not much

Rick, in the case of surface agitation more is better. You want to provide as much as you possibly can. That's one of the reasons hex shaped tanks and very deep tanks are less than ideal, and why the majority of tanks are built as rectangles and not squares.
Best off to think of those places in your tank where water falls (into overflows, over baffles in the sump) as bonus places where you are adding oyxgen, but equally important is the removal of carbon dioxide as it is continually being released by your fish & sandbed (we don't see the CO2 the bulk of the time, but it's there!), and those small areas you mention in your tank are not sufficient to provide the optimum amount of exchange.