I am no fan of reflectors, but not of kool tubes or heat glass either.

I would take it out of there and spread the MH light around so it overlaps in spectrum more than it is.

If heat is an issue, then yea, kool tubes are the way to go then.

I believe that UV rays increase potency of the THC present. GLass will block the UV-B rays that affect that.

The glass will allow the UV-A rays to penetrate but it is the UV-B rays you want.

But still I would broadcast the light over a wider area.

But I think you have done nicely without my advice...