How well does aluminum foil block radiation?

[Raizy]

I bought one of them grow lights for hydroponics recently - 400 watts Metal Halide and I wanted to know if a makeshift aluminum foil wall would be good enough to block out the radiation coming from the lamp. I know the outer glass shell of the light bulb already acts as a filter but i just want to be extra safe. The position of the growing area is only 4 feet away from my computer desk and I will be exposed to this lamp for several hours a day.

Here are the wavelengths the light bulb emits (my bulb type is "Neutral Deluxe")http://www.sunmastergrowlamps.com/SunmSpecFam.html

EDIT: Furthermore, the fish will be near the light source aswell, will the fish get harmed?

 

[DaveC426913]

What radiation are you trying to block? It will certainly block visible light and UV.

 

[Raizy]

Just the ones harmful to humans.