Lids Filtering Light?

[littlebigreef]

I use 1/4" ( 0.22" ) Clear Extruded Acrylic Plexiglass over my 125 gal refugium. I've had to keep the pieces over the fuge more often to cut down on evaporation. However, I've notice that the corals don't do as well. I'm currently running a 6' T-5 unit with recently replaced bulbs. I've stayed away from glass as its my understanding that certain types of glass filter out beneficial light. Yet, going to a thinner plexiglass- 1/8" ( 0.118" ) leads to the material bowing and warping. Is there a better way?

 

[aKlevans]

The best method would be to get a screen net top and an ato. However, this may not be very cost effective, so you will have to make some trade-offs.

 

[littlebigreef]

The best method would be to get a screen net top and an ato. However, this may not be very cost effective, so you will have to make some trade-offs.

I have an ato so I'm less concerned about that and more about the amount of moisture going into the air. I'm all for trade-offs I'm just wondering if there's a material that's widely recognized as the go-to for solid lids that minimally impacts reef lighting.