Is my light too close?

[Tead]

I'm running a cool tube with dedicated ventilation and a 400W HPS bulb.
I know that, as a general rule, the closer the lights to your plant, the better.
I read in the forums, especially in the Joys Of Growing - Great Guide! thread, that 3000 lumens is the optimal target.
My light should be putting out 5500 lumens. I believe that's a measured at 1 foot from the lamp.
The bulb of my cool tube is 1 foot from my canopy top.

I'm concerned that the angle of the light hitting the growth near the edges of light coverage might be too severe.
Maybe the light would be more effective if coming from a higher angle. Maybe the trade off between lumens vs light angle would be worth it.
My motivation here is that I could probably squeeze 1 more plant into the mix if I raised the light a bit.

Thoughts?

 

[Dan Ultra]

I have the same set up, 400w MH with cool tube, and I have it set 10" above my girl. No signs of heat damage as of yet. Mine is still small and I am fluxing to keep it really low, so I dont know how much it differs from you needing the light to spread out more. What kind of reflector do you have?

**edit** 10" from the cool tube, so I guess that would be equal to 12" from the actual bulb.

 

[c526]

have a look over in hunternitro lsd thread, he does a little testing with a cooltube and a lux meter.

 

[Tead]

I have the same set up, 400w MH with cool tube, and I have it set 10" above my girl. No signs of heat damage as of yet. Mine is still small and I am fluxing to keep it really low, so I dont know how much it differs from you needing the light to spread out more. What kind of reflector do you have?

**edit** 10" from the cool tube, so I guess that would be equal to 12" from the actual bulb.

I have a wing reflector on the cool tube. The tube itself has an internal reflector that covers the top 1/2 of the cool tube. 10" is the bulb height. Heat is not an issue at all. I could get the tube closer without damage. I'm shocked at how efficient the tube is at cooling.

 

[Tead]

have a look over in hunternitro lsd thread, he does a little testing with a cooltube and a lux meter.

Spot on c526! Answered all my questions. I think I'm good where I am. I might even look at moving from 400w to 600w. 600 seems to be a sweet spot. That chart was perfect. Thanks!

 

[Dan Ultra]

I have a wing reflector on the cool tube. The tube itself has an internal reflector that covers the top 1/2 of the cool tube. 10" is the bulb height. Heat is not an issue at all. I could get the tube closer without damage. I'm shocked at how efficient the tube is at cooling.

I am surprised as well!! I can basically keep my hand at the glass with no problem. I have mine hooked up to a 240cfm extractor fan

 

[Tead]

I know. Even in the summer heat where the input is much warmer, I've never felt any significant heat from it.

 

[Tead]

Here's a shot of the light in place...

 

[Dan Ultra]

yep. mine looks just about the same except I have the bulb end open with no ducting. You can bend up those reflectors to make them give a little bit broader footprint.

 

[Tead]

The duct may be on, but it's currently venting into the grow area. Free heat!
When the weather gets above 70 regularly, I'll port it back outside and put the A/C back in the loop. My world is built around a hot environment so the few months of cold can be a challenge.

 

[Dutty Panty]

Spot on c526! Answered all my questions. I think I'm good where I am. I might even look at moving from 400w to 600w. 600 seems to be a sweet spot. That chart was perfect. Thanks!

Not sure if you looked at any of my threads but if your thinking of going 600 hps my info may help. I run 14, 600 watt hortilux hps bulbs and lumatek dual 600 ballasts So I can run two bulbs per ballast. I have a lux meter if you need readings as well.

 

[Dutty Panty]

The duct may be on, but it's currently venting into the grow area. Free heat!
When the weather gets above 70 regularly, I'll port it back outside and put the A/C back in the loop. My world is built around a hot environment so the few months of cold can be a challenge.

I ventilate my exhaust from bloom right over my recliner with a floor register in the ceiling and another register in a hallway works great. No smell and when I'm just watching TV smoking my herb my bloom heats me up.

 

[Dutty Panty]

yep. mine looks just about the same except I have the bulb end open with no ducting. You can bend up those reflectors to make them give a little bit broader footprint.

That's the number one reason I use econo wings. I used to run all blazer 8's for cooling reason but my footprint was extremely limited good call dan.

 

[Dan Ultra]

That's the number one reason I use econo wings. I used to run all blazer 8's for cooling reason but my footprint was extremely limited good call dan.

I'm gonna have a look into these. Do the fit to cool tubes okay?

 

[Tead]

Not sure if you looked at any of my threads but if your thinking of going 600 hps my info may help. I run 14, 600 watt hortilux hps bulbs and lumatek dual 600 ballasts So I can run two bulbs per ballast. I have a lux meter if you need readings as well.

OH Nice! Thanks. I might hit you up for that when I upgrade. I may get a light meter myself. I've been wondering what the readings are inside my plants.