Originally Posted by Travis55
What about chrome spray paint?
To be honest Travis55 you would have difficulty keeping chrome paint even and it probably wouldn't obtain the same reflectivity as leaving it white.
Keeping it white as it is you should be getting around 80% reflectivity.
Tin foil with zero creases around 85% reflectivity.
Chrome paint with even coverage maybe if you're lucky 85% reflectivity.
However with chrome paint I would be concerned with offgasing.
Seriously I would leave it white as it is, I used to use diamond reflective sheeting on walls. My reflectors that housed my 600w lamps used to have a bubbled aluminium reflective panel above them but it was also computer designed to give the best spread of light downwards.
With metal halide lamps have you thought about water splash on the glass tube?
The reason I ask is that MH
Lamps use gasses to ignite and keep the light spectrum you need and they burn hotter ALOT hotter than T5's T8's etc so a small amount of water on the glass tube could cool the bulb too much and cause a blow out.
This would obviously depend on the proximity of the MH
to the water level.