You may want to remove the fingerprint oil you're getting on that HPS bulb with some non-residue volatile solvent. Not supposed to handle them like that.

And unless you're using a tempered glass enclosed reflector/hood, I'd wear eye protection if you're even thinking about working with water, nutrients, etc. around an energized bulb. That'd be an unfortunate 911 call; blinded and busted in one fell swoop.

The drain pan's a fine idea, as long as you don't use it as a drain pan. There shouldn't be any standing water anywhere, and you don't want your plants to easily share contaminants/infections.

Stay safe,
Hermie.