Algae I need to be concerned with?

Hi everyone. I have a question about some algae I spotted growing under my substrate. I have a 65 drilled DT with sump. When I get my head in under the tank and look up through the glass I can see reddish dark brown algae on the glass just under witer my LV is sitting in the tank. The tank has been online for 2 years now. I would hate to have to move the LR to clean this algae,...is it something I should be concerned with?
I'm wondering if the sump / fuge light has anything to do with it growing and maybe I should cover the underside of the tank to prevent light from getting to it?
Thanks.
Chris

 

Well as long as things are in check not much you can do and moving all the live rock (depending on sand bed and if you partially clean it sometimes) will only release gases and nasty stuff.

IMHO +1 to putting something between light and underside of DT if it has no type of hood or light canopy built into it.

 

+1 on both of accounts, i wouldn't want to risk the release and the algae should die off without any light.