water cooled lights

[Rusty Trichome]

I have been told that useing a mh for flower makes the buds more dense, and have also been told that useing mh+hps is even better then just one by itself.

Hmmm...I've heard (but I don't utilize the technique) that MH can help slow early flowering stretch, but is ultimately the wrong spectrum for proper flowering.

I'd tend to do as the experienced growers do, since there's years of trial and error backing their techniques, but that's just me. :jointsmile:
Plus, I have two grow rooms (one flower room, one veg room) and switching light and ballast between rooms is an unnecessary bitch.

Perhaps if you only have one growspace, and you already have the MH to suppliment your HPS, and can afford the electricity that the limited benefits will cost you, and can deal with the extra heat it throws-off...then sure. Go for it. I believe I've heard a 2:1 (HPS:MH) is "desireable", but...I only use HPS for flower. Works great.

MH makes more potent buds...? Got a link for that one?

[Opie Yutts]

I've taken to adding some bluish CFLs (5800K) in with my HPS. It has increased density and stickiness, no doubt. It is best IMO if you can do about 85% blue and 15% red in veg, and the opposite in bud.

[Opie Yutts]

Cooling lights with water. Sounds interesting. Here's another: Texas Hydroponics :: Grow Lighting :: Liquid Cooled Lights :: Liquid Lumens "HydroFlector" Reflector Insert