It is down to your personal situation. Find yourself a clip on or occilating fan to blow on the bulb between the bulb and the plant canopy. Light dissipates rapidly. Every foot or 30cms light has to travel, the intensity is reduced by half. Every foot away the bulb is from the plants you are dividing your lumens by half each time, this is the reason people use cool tubes and not open ended reflectors.
MegaOctane12 Reviewed by MegaOctane12 on . questions!!!! hi all, just a few questions...... 250w hps 12 hour (12hr x 0.25kw = 3kw) will consume 3 killowatts, kwh @ £ 0.12 = £ 0.36 for 12 hours is my math correct????how far does the 250w hps have to be from the tops of the plant????? how long do vegg for, is it untill it reaches a foot?? and do you introduce the 12/12 flowering cycle slowly i.e -1hr 1st day -2hr 2nd day etc....???????:rastasmoke: thanxs morning glory Rating: 5