Acrylic vs. Glass

[RossW]

I have heard that acrylic blocks much less light than glass.

I noticed that both ATI and Tek provide acrylic shields on their lights.

Does anyone have any hard numbers on different types of materials and how much light they block?

[nissannx]

i have a mixture of both glass and acrylic top on my tank with t5 bulbs. i cant see a difference with my calibrated eye

[johnrt]

If you want to protect your T5 bulbs and reflectors, you might look at that "shrink wrap" plastic that is sold at this time of year at Home Depot and other places as cheap window insulation. Once shrunk with a hair dryer, it is quite flat and it is so then that it cannot absorb much light. Remember, absorption is linearly related to light path-length - thickness.

You will probably still need to make some allowances for ventilation an cooling of your fixture and best not used on MH systems.

You might make a frame out of some rigid material and put the film on it and suspend it below your lamps with an air gap.

Just some thoughts.

John T