Yield Decrease w/ DE HPS from SE HPS???

[zachrockbadenof]

yes id say atleast 36" and more like 42"
Are the Single end or double end?

single end 1000w hps's

 

[Chilly Willy]

I have averaged pretty consistently 1.07g and that is using MH for six hours, and HPS for the other 6 hours; if I used all HPS for the entire 12 hours the yield would be higher, but not as good of quality. I go straight by the charts, feeding them using the Bontanicare chart they supply, and using the charts showing the intensity of the light how far it penetrates. No glass under the hoods, intermittent fans, and heavy Co2.

I keep the lights real close to the top of the canopy because my bulbs only penetrate about 11 to 12 inches depth at full strength of the sun. So the more distance I allow between the hood and the tops, the less penetration I have into the canopy.

I checked the chart for you, and it says 20 inches for a 1000 watt bulb is 100% full sun intensity. I was using 600 sq. ft size area to dissipate the heat given off from a 32 sq. ft. grow area, using three 400 watt bulbs (alternating from MH to HPS). I don't know how you guys run such large bulbs in small footprint spaces, do you exchange the air with the outdoors every few minutes?

I think your lights need to be closer, and something else needs to be done to dissipate the heat. The charts above, one is for HPS, the other MH.

Just curious, did I do my calculations correctly. 1200 watts divided by 1120g (38 plants) = 1.07g per watt?

The primary reason why I only used HPS half the time is because the MH keeps the node distance very close, I skip veg state, and the plants stay short in height. By growing more short plants and less taller plants I am abble to use 400 watt bulbs, and this keeps the room cooler. I noticed it was hard to keep the temps down to 78, and noticed they would want to stay around 82 because the ac unit would not keep up so I said screw it and bought a big Co2 burner and ran high amounts of the gas so that it odes not matter now so much the higher temps. I pretty much just let the ac unit barely run, and let it stay hot in the area.

I was afraid to use glass on the hoods because it may affect the violet portion of the MH spectrum, and those vortex fans are stinking loud anyway and did not want to have to use more than one of them. The vortex distributed the air between both sides of the apartment and that was enough for me. The only time I had problems with not enough humidity was in winter, here I had to buy one of those humidifiers that parents buy for their kids when they get sick, I think mine was a penguin (just my luck, that is also my avatar).

 

[AWDTERROR]

Your gpw is .9333
Personally to me 20" from canopy is Waaaay to close to the canopy. Alot of times in life "more" is not always better