Will algae grow under tank from sump light?

[ChrisNH]

I was wondering if a tank on a stand with no top (so bottom is exposed) will grow algae on the bottom from a refugium light in the sump?

If so, would that algae contribute to algae in the display?

Currently my 40B is sitting on top frame of 2x4s I just finished rebuilding to fix a leveling issue and I was wondering if this would be a thing.

 

[Reefer Reboot]

From my experience, yes it will. But running bare bottom, it was only a matter of time until the Coralline Algae covered the bottom. (Then the GSP covered that.)

 

[rkpetersen]

A minimal layer of sand would block the light and prevent significant algae growth.

 

[ChrisNH]

A minimal layer of sand would block the light and prevent significant algae growth.

That would not apply for light shining up on the bottom from the sump