Why submerged screen dont grow algae?

[jnad]

Hello!

I have a question for you:

Why dont a submerged under water screen grow any algae?? With same light and flow as in a standard scrubber configuration?

jnad

[kiddjam]

this is the question that i thought of too, but i know the answer.

because: the surface/screen's contact area with the water will greatly reduce if submerged, hence, algae spores in the water won't grow on the screen purposely.

[Ace25]

Good question, and honestly not quite sure of the answer myself. I still get green algae on the 1" below the water on mine.. but it never grows long algae like the rest of it. That would be my question, why does algae grow long from the walls/floor of my sump (using the same LEDs that are pointing at my screen, so it is very little incidental light hitting the sump area to grow algae, but it still grows great), and it grows great on the screen above the water line, but the 1" of screen submerged is the only place it doesn't grow long. Not that it is an issue at all... just one of those "why does that happen" type of things.

[SantaMonica]

We've covered it in the past which you may not have seen... the high velocity of the thin waterfall removes the boundary layer around the algae molecules. With less boundary layer, more nutrients can get into and out of the algae. When the layer of water is thick like in a sump or display, it may appear like the layer next to the wall is flowing, but it's actually stopped. You can google "boundary layer flow" for more info.

[Ace25]

Sounds good to me.

[Rumpy Pumpy]

Submerged rock, on the other hand, seems to be able to grow lots of algae.

[whites]

I think the out come is yes it can grow under water but to get the max benifit out of it the curtain of water is the best to do so??