DIY Lighting

[Cdfortin]

I'm building a 440 watt compact flo canopy and need a clear plastic division between the lights and water. What's the exact name for the plexi-glass-like stuff that protects most prefab compacts/halides?

Thanks!

Dan

[JProx]

acrylic is a common term, plexi glass is the other,

however it might be cheaper, to use glass, try calling a local glass shop and asking what the price would be for your needs, it should be close, or cheaper than acrylic.

[Cdfortin]

Is there any difference between acrylic, lexan, and plexi? I thought I heard somewhere that plexi would melt...btw i really don't want 2 use glass because of is weight and ability to break. This is a very large, 440 watt CF fixture (5 feet long 2 feet deep). Can anyone clarify this? Thanks!!

[jsoong]

There are different grades of acrylics. The cheaper types are extruded, not as dense. More expensive are cell casted, denser & supposed to be stronger & optically clearer.

Lexan & Plexi-glass are all trade names, there are many more. I can't remember which is cell casted <I think "Plexi DL" is> ... a good plastics place should be able to tell you. Lexan is supposed to be polycarbonate <sp?> which is supposed to be stronger & more heat tolerant.

Lexan would be your choice for heat, but all acrylics would eventually melt or sag at high enough temperature .... so glass might be a better choice.

[jsoong]

Found a page with all the different terms & brands of acrylics, here it is:
http://www.signweb.com/fabrication/cont/shapeshft8.htm

More accurate than my memory!

[JProx]

cdfortin, jsoong sorry for being a half arsed poster, i should have clarifed alot more than i did.

[youronlysin]

A lot of lights.....vehicle headlamps, driving lights, halogen light fixtures use Polycarbonate lenses. I dont imagine a 5 foot by 2 foot deep piece is real cheap. Good luck.

[Aquathumb]

Wow. 440 Watts!!!??? Do you mean (4) 40 watts?

I used the Coral Life End Caps w/ 6 T-12 40 watt fluorescents on the hood I built for the 125 and they work great. They came with clips to hold the bulbs in place inside the hood. If you check out my photos you can see the hood on the 125 w/ lamps.

Remember that glass will filter U.V. and result in dimished results, including promotion of algae growth. Same reason why you can't get a sun tan through the windows of your car. Any type of lexan, plexi etc. will will also restrict the light that actually reaches the contents of the tank. Any reason why you wouldnt have the bulbs directly over the water providing you have waterproof caps and the balasts etc. are located outside of the hood?

[Aquathumb]

Wow. 440 Watts!!!??? Do you mean (4) 40 watts?

I used the Coral Life End Caps w/ 6 T-12 40 watt fluorescents on the hood I built for the 125 and they work great. They came with clips to hold the bulbs in place inside the hood. If you check out my photos you can see the hood on the 125 w/ lamps.

Remember that glass will filter U.V. and result in dimished results, including promotion of algae growth. Same reason why you can't get a sun tan through the windows of your car. Any type of lexan, plexi etc. will will also restrict the light that actually reaches the contents of the tank. Any reason why you wouldnt have the bulbs directly over the water providing you have waterproof caps and the balasts etc. are located outside of the hood?