There are HPS bulbs that I know of that are designed to hang vertically but there MUST be extraction through some kind of cooltube. The plants have full 360degrees coverage from the bulb and not just half you get when hanging horizontally but I'm sure theres some hidden price to pay for growing this way. Also the first pic looks like that because he has trained and topped his plants, there's nothing to say that the results would not have been the same or better if the bulb was horizontal.
MegaOctane12 Reviewed by MegaOctane12 on . hanging your light downward i just game across a person using thier HPS light hanging down, now i never did think this would be a better way to use your light but now it has me thinking........can you possibly get better light coverage having the light between plant or atleast close to it. look at this pic. its nothing more than a 250watt light attached to a cooltube, that is a amazing grow with such a small light. would do you of this way? Rating: 5