[p0opstlnksal0t]

Im looking at bringing another 2x 10x10 (7' ceiling height) tents online.... my hope was to run 1kw of lighting per 4x4 footprint inside the tents... should I be looking at cooled single end HPS? A few years ago I was able to pull about 700 grams average per 4x4 area under 1kw SE air cooled light. Would I be able to get this using 270w LED light rails, Two 270w led light rails per 4x4 area?

There's a guy up here in New England selling homemade led's for 260.00 per rail:

38" x 4". 5.5lbs

Gen3 3000K chips from Luminus. All Meanwell drivers. Active cooled, aluminum rails with 4 chips on each. 288watts. (272w (68w per led x 4)+ 16w for fans).

All intel fans

Data: Chip profiles @ digikey: https://www.digikey.com/product-deta...4-3-ND/6151616

[2011rex87]

Mmm.. I checked out the link and the actual chips look good.. However, 700 grams finished weight from 2 of those rails is pushing it. I think all other grow factors would have to be 100% on point for you to pull that but it IS doable. I would not get a SE HPS either, though, because that technology is very old and has been replaced by Double Ended HPS as you may already know. You can retrofit a SE HPS hood to use the DE HPS lights in most cases. Some DE HPS fixtures can run 1200w as well for an added bonus.

https://hightimes.com/grow/grow-gear...-single-ended/

"
Double-ended (DE) HPS bulbs connect to the fixture on each end much like fluorescent tube bulbs. In this case, the inner, light-generating tube is supported by two small wires on each end of it, and lacks a frame wire that crosses in front of the arc tube. Without any of the metallic structure SE bulbs need to support the arc tube within the bulb, DE bulbs are significantly thinner than SE bulbs.
Exposing the arc tube to the bulb without any metal framing in the way increases light delivery to the canopy of your plants. The symmetry of DE bulbs allows you to create an even spread of light much easier than is possible with SE bulbs."

Let us know what you end up doing. Post some pictures for us when it's all setup!

[p0opstlnksal0t]

Originally Posted by 2011rex87

Mmm.. I checked out the link and the actual chips look good.. However, 700 grams finished weight from 2 of those rails is pushing it. I think all other grow factors would have to be 100% on point for you to pull that but it IS doable. I would not get a SE HPS either, though, because that technology is very old and has been replaced by Double Ended HPS as you may already know. You can retrofit a SE HPS hood to use the DE HPS lights in most cases. Some DE HPS fixtures can run 1200w as well for an added bonus.

https://hightimes.com/grow/grow-gear...-single-ended/

"
Double-ended (DE) HPS bulbs connect to the fixture on each end much like fluorescent tube bulbs. In this case, the inner, light-generating tube is supported by two small wires on each end of it, and lacks a frame wire that crosses in front of the arc tube. Without any of the metallic structure SE bulbs need to support the arc tube within the bulb, DE bulbs are significantly thinner than SE bulbs.
Exposing the arc tube to the bulb without any metal framing in the way increases light delivery to the canopy of your plants. The symmetry of DE bulbs allows you to create an even spread of light much easier than is possible with SE bulbs."

Let us know what you end up doing. Post some pictures for us when it's all setup!

DE HPS wont be an option seeing as i have 7' ceilings to work with. I know I can pull 700 grams of dense high quality herb off a 1000w digi and an air cooled hood and i can get the light fairly close to the canopy unlike a DE HPS setup. This is going in a tent in a basement with 7' floor to top of tent height. it looks like my only options are to run 4kw worth or air cooled SE lights, about 2.5kw worth of cmh (630w per 4x4 area) or run 2160w worth of LED ( 540w per 4x4 area). the LED seems the most tempting if it can produce in the 1.2-1.5 gpw. running costs are low and up front cost is only slightly more per 4x4 area.

[2011rex87]

You could run the DE with 7' to work with. It's not going to produce more heat than the SE if you are comparing 1000w to 1000w SE to DE. The article explains that the bulb is simply more effective at delivering the light to your canopy. So if you can run the SE aircooled with 7' you should be able to run the DE. I could see how you would be reluctant to make the purchase though only to find out later that it indeed won't work for you. Seeing as you are already used to using SE and are comfortable with that - it makes sense for you. Prices are coming down on those SE fixtures and bulbs because demand is so high for the DE now so you should be able to find some good deals. Wishing you the best of luck hope to see the pictures!

[p0opstlnksal0t]

the problem with DE's is that you cant air cool them, the bulb has to be exposed. which is why an SE would work better because it can sit in an air cooled hood and not fry the top of your canopy.

Ive also got these 2 PL Light NXT2's kicking around, maybe i should just get 2x more DEva's and run 4x of these DE's at about 600w each. get a cheap 240v light timer and call it done... still ive only got 7' ceilings down in the basement, not sure if these DE's at 600w will fry my canopies...

Ive also got these 2 PL Light NXT2's kicking around, maybe i should just get 2x more DEva's and run 4x of these DE's at about 600w each. get a cheap 240v light timer and call it done... still ive only got 7' ceilings down in the basement, not sure if these DE's at 600w will fry my canopies... in my big flower room i caused light stress on my canopy @600w with about 40" of height. this was also a transplant from T5's so a little shock but still. these DE's put down some serious radiant heat to the top of the canopy unlike an encased SE thats got 600cfm of air blowing through the hood and past the bulb to cool them. the SE isnt as efficient for sure but in low ceiling heights im kind of stuck.

[CrossBones]

I had been running a air cooled HPS in a basement 2x4 tent, ventilation pulling from inside the tent, had a real problem keeping any humidity in the tent this winter, switched to some cheap leds to try and am able to keep humidity in range easily.. Just something else to consider with the changing seasons, even this past summer I was a bit dry in there, but more doable.. Thinking I may be a led convert, only because I can more easily keep the environment more grow friendly... Just get the correct light colors for what your after if you go led.. My 2 cents from a noob..

[p0opstlnksal0t]

Originally Posted by p0opstlnksal0t

the problem with DE's is that you cant air cool them, the bulb has to be exposed. which is why an SE would work better because it can sit in an air cooled hood and not fry the top of your canopy.

Ive also got these 2 PL Light NXT2's kicking around, maybe i should just get 2x more DEva's and run 4x of these DE's at about 600w each. get a cheap 240v light timer and call it done... still ive only got 7' ceilings down in the basement, not sure if these DE's at 600w will fry my canopies...

Ive also got these 2 PL Light NXT2's kicking around, maybe i should just get 2x more DEva's and run 4x of these DE's at about 600w each. get a cheap 240v light timer and call it done... still ive only got 7' ceilings down in the basement, not sure if these DE's at 600w will fry my canopies... in my big flower room i caused light stress on my canopy @600w with about 40" of height. this was also a transplant from T5's so a little shock but still. these DE's put down some serious radiant heat to the top of the canopy unlike an encased SE thats got 600cfm of air blowing through the hood and past the bulb to cool them. the SE isnt as efficient for sure but in low ceiling heights im kind of stuck.


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I will probably run 4 plants in each 4x4 area. the buckets are probably 12" tall so that leaves 6' from top of bucket to bottom of tent. the lights will take up the top 1' so thats 5' from top of bucket to bottom of light.... if I give myself 30-36 inches from canopy to light bottom this gives me 2' to 2.5' from the top of the bucket to scrog the canopy down...

[FlaDankster]

Since LED is one of your options have you looked into Quantum Boards?

[Pro Headies]

https://horticulturelightinggroup.co...oducts/hlg-550

This is the only LED id buy if i was replacing my 1k HPS's

[2011rex87]

As I said before..DE Hps can be air cooled. You can retrofit the old SE HPS hood to work with DE. I can post pictures if needed... I have DE HPS in a raptor xxl air cooled hood right now.