with light, algae can build up in the reaction chamber significantly reducing the efficiency of the skimmer and requiring frequent cleaning. If I recall, the remora pro has opaque sides and back, but I think the side facing the aquarium is translucent, which would allow light to enter the reaction chamber. If you paint this side it shoud help! (besides, being a past owner of the remora pro, I know what a pain it is to try and clean all the way down inside that thing)
best of luck!