I also wanted to show people why you really need a top reflector but it needs to be a proper type.

Reflectors are designed to reflect light...duh....

But, in doing so, if they are metal, they reflect back heat as well. Too much too often. It prevents you from getting your lights as close as possible to theplant top...even with the fan blowing.

This is because metal reflectors create a 'radiant heat'.

It is a heat ray emitted in the form radiant energy. This energy cannot be 'blown away' with a fan and can barely be cooled with an AC unit on it.

They are plain and simple heat rays that are impervious to most any atmospheric conditions except say cloud, shade cover or moisture.

However, failure to have a reflection unit results in massive loss of light that could and should be reflected on the leaves surfaces of the plant.

In my setup, I have a WHITE board, which difusses the light really well but blocks most of the light above it and reflects it back down. It can do this without the radiant heat issue as the wood will absorb more heat as it is thicker than the metal reflectors and spreads the heat over a wider area.

Metal reflectors will quickly reach their heat absorbant capabilities or limits.

After this level is reached, ALL HEAT IS REFLECTED BACK. NO MORE HEAT CAN BE ABSORBED.

The wood never absorbs so much heat that all heat is reflected.
With a strong exhaust, the air is sucked out from the sides of the reflector while minimizing the light loss.

Pay attention to your grow area. If you are losing light at the top, you are not giving your babies the light they could be using.

I have also found white paper card board to be a good heat absorber but also a highly reflective surface. Whatever you use, use something other than a metal or aluminum reflector.

Just my lowdown on reflectors and the heat issues.

The results peak for themselves, yes?