Do eggcrate/ light diffuser lids affect PAR from Aquarium lights above?

[dimitrinivo]

I have an eggcrate lid, its that material that frag plugs sit on top of in frag tanks. Its made to be used as a light diffuser, with this in mind, does it affect the PAR values from my light which sits directly on top of it?

 

[JCTReefer]

Maybe this will help.

Effects of various aquarium covers on light transmission

I got a private message from GaryE and thought my reply might be of interest to others. Here’s the message: I know you have done innumerable studies on the various different lighting packages available. Have you ever studied the effects of different coverings on PAR levels? Specifically, I'm...

www.reef2reef.com

 

[Weasel1960]

As an architect the egg crate diffuser was designed to focus light down, not out, but over the distance from the ceiling to a desktop in an office....about 7 feet. I would think you will get some hot spots going straight down into your tank but at angles it may be very shadowed because then distance is much shorter.

BRS did a video on different screen mesh sizes And only found a 4-8% different from no screen at all. I plan on using screen for that reason and aesthetically it will also blend into the tank from a distance.