light through glass

[sryder]

can any one tell me how much light is lossed through glass tops?

 

[bc_slc]

can you be more specific? with what type of lighting, over what dimension of tank with what type of energy source for the lights? NO vs VHO vs MH vs pc will make a big difference.

 

[bradreef]

the problem is the saltwater that dries on them. this will block most of the light. Look at sanjays studies on MH bulbs he shows the difference between shielded and unshielded light. the glass can be thinner and clearer though.

 

[sryder]

i was just wondering how much light would be lossed through the typical 1/8 in canopy glass. most salt creep if any would accumilate on the top of the glass and can be wiped clean. the underside is usually covered in condensation. i just saw somewhere that glass tops can cut 22% of light. that seemed realy high to me. i thought it was alot less. i know that light can bend at the point of contact especially if the light source is angled to the pane. someone also stated that the lead in the glass has alot to do with it but i have not seen any studies to prove either way. i would be curious as to all 3 types of lighting. normal strip flourescents, pc, and halides. i personally like the tops they help with keeping things in. my tank is in the basement and runs cool. most air exchange is done through my skimmer, sump, overflows etc. my only concern would be the light loss. i would love to see some studies pertaining to such. steve