OLH Optimum Light Hight Question: 250HPS Vented

Im running a 250w hps with glass and its vented with a 4inch can fan.

Room runs about 77 degrees.

How high should my light be from plant tops.

My plants range from 3 to 5 weeks in age.

Up for some responces... Thanks.

BigHoseExpert said:

Up for some responces... Thanks.

Click to expand...

Check these..

at seedling stage like a foot away, but for vegg and flowering as close as u can without burning them.
test the distance by placing ur hand under it, if its too hot for u its too hot for the plants


Cheers

How far away from my plants do the lights go?
The lights in your grow room should be as close as possible to the plants without burning them. There is no such thing as too much, unless there is sufficient heat to dry out and burn the leaves. A good rule is to put your hand under the light, if its too hot for your hand, chances are that the plants will be too, so move the light up until your hand feels more comfortable. For seedlings and clones, I keep them a little further away from the light, because they are very susceptible to burning and drying out, at these stages.

Efficiency is very important when choosing a type of light. The wattage is not the most important thing, as you can see below, different types of light produce different amounts of lumens per watt. A 300 watt incandescent will produce about 5100 lumens. While a 300 watt Metal Halide (just an example, they do not come in 300 watts), will produce 27,000 lumens. Obviously far more efficient for growing, while still using the same amount of electricity.

I put mine a few inches away and it bleached the leaves. I grow dwarfs (lowryder2) so that may not happen with regular plants. Move the light up to about 7 inches above the top and the bleaching corrected itself. You may not mind a little bleaching at the top if it gets the light down further into your canopy.