Mixed LED and LEC replacing HPS watt for watt ? What to expect? Tips please.

I have been growing for a couple decades now and seem to have everything dialed in. I am taking a step in one of my rooms to new lighting tech looking for comments and recommendations on set up.

I am late to the party but better late than never. I have sworn off high priced LED's for the longest time. I have been waiting for them to get better and cheaper with time. Also, waiting to see some grows that produce hps numbers and quality and I have seen a few so figured I would give it a whirl.

I have a 5 x 15 room that I used to have qty 3 1000w hps lamps in. The room is actually 8 x 20 but need space to move around so the 5 x 15 will be the space for the plants themselves.

I am setting up a mixed spectrum of LED and LEC lights. I will have qty 8-280w 2 panels quantum boards and qty 3-315w cmh (lec) for a total of 3185 watts of power from the wall.
I plan to have it set up with the cmh between qty2 LED's. Each LED has 2 samsung boards with the new 301h diodes.

So basically:

LED - LED - CMH - LED - LED - CMH - LED - LED - CMH - LED - LED and this should cover the whole room and have them basically wall to wall with minimal spacing between the lights.

I guess my questions are, is this an overkill? Would you all recommended running them at lower power at first? How much heat should I expect? The lights are all purchased and delivered, I just have to set them up. Any tips and opinions appreciated.

I am having a hard time keeping my canopy temps high with just LEDS so I think you are on a great track with the mix of CMH and LED. I will have to do something about it after this grow, for this grow I'm gonna focus on soil pH, nutrients, and using my new quantum boards. Next grow I'll work on controlling VPD..

I see what you're talking about with the row of led-led-cmh-led-led
Another possibility, since the CMH may have to be a little bit higher is putting them in the center of the room , with the LEDS surrounding them, so if you need the led's lower they aren't blocking out the light from the CMH's that are higher up in the room. you could also angle the leds a little if needed or hang them horizontally for side lighting

another issue with having the whole top of the room filled with lights could be airflow. I found this awesome thread where this guy uses a ton of knockoff boards, and is a really good visual.

Nizza said:

I am having a hard time keeping my canopy temps high with just LEDS so I think you are on a great track with the mix of CMH and LED. I will have to do something about it after this grow, for this grow I'm gonna focus on soil pH, nutrients, and using my new quantum boards. Next grow I'll work on controlling VPD..

I see what you're talking about with the row of led-led-cmh-led-led
Another possibility, since the CMH may have to be a little bit higher is putting them in the center of the room , with the LEDS surrounding them, so if you need the led's lower they aren't blocking out the light from the CMH's that are higher up in the room. you could also angle the leds a little if needed or hang them horizontally for side lighting

another issue with having the whole top of the room filled with lights could be airflow. I found this awesome thread where this guy uses a ton of knockoff boards, and is a really good visual.

Maximizing Yield using Citizen Cobs, QB knockoffs, and Philips CMH

I welcome anyone to comment good or bad on my grows.. I have 2 bloom rooms, both have LED designed for a 6x12 footprint and both use a 6x12 screen. One room uses 72 Citizen 1212 3500k cobs powered at about 48 watts each (1 cob/48 watts per sq/ft). The second room uses 60 Mejiu PCB boards aka...

www.rollitup.org

Click to expand...

Good advise and a good read. Thanks for sharing. He really killed it with those cobs and panels.

Nizza said:

I am having a hard time keeping my canopy temps high with just LEDS so I think you are on a great track with the mix of CMH and LED. I will have to do something about it after this grow, for this grow I'm gonna focus on soil pH, nutrients, and using my new quantum boards. Next grow I'll work on controlling VPD..

I see what you're talking about with the row of led-led-cmh-led-led
Another possibility, since the CMH may have to be a little bit higher is putting them in the center of the room , with the LEDS surrounding them, so if you need the led's lower they aren't blocking out the light from the CMH's that are higher up in the room. you could also angle the leds a little if needed or hang them horizontally for side lighting

another issue with having the whole top of the room filled with lights could be airflow. I found this awesome thread where this guy uses a ton of knockoff boards, and is a really good visual.

Maximizing Yield using Citizen Cobs, QB knockoffs, and Philips CMH

I welcome anyone to comment good or bad on my grows.. I have 2 bloom rooms, both have LED designed for a 6x12 footprint and both use a 6x12 screen. One room uses 72 Citizen 1212 3500k cobs powered at about 48 watts each (1 cob/48 watts per sq/ft). The second room uses 60 Mejiu PCB boards aka...

www.rollitup.org

Click to expand...

The hanging height of the cmh should depend on reflector: with batwing we had our 315 (op never mentioned what wattage bulbs) at maybe 12 inches in aisles with a sorta stadium dip in the middle. 280w 2xqb fixtures generally would go higher i think, start out at 18-20" if on max.

As a general idea for dialing in: start with cmh at high temps, 81-84 and bring in led slowly. I find it easier to dial in by using hanging height than dimming.

These are my humble notions from having seen led and cmh in openrooms

Invest in a good par meter you have spent so much already just get the $500 apogee and make sure the light is nice and even. a $10 infrared thermometer is a good buy too so you can compare leaf temps of the cmh plants vs the led plants you might need to run slightly lower ppfd under the cmh to keep the leaf temps the same as the led focused plants because of the difference in IR

The good thing about mixing led with cmh (as opposed to hps):
They are both right in similar temps. The amount of ir in cmh is much less than in hps so you can run your cannopy at the same temps as a led cannopy 84ish F. This summer was scorching we had 30c(90ish Fiirc) at our cmh cannopy aand it turned out fine.

Op, you could even try a pure cmh side versus a pure ledside.. might be easier with hanging height

Again, im talking about 315s, no exp w 630s.

Rocket Soul said:

The good thing about mixing led with cmh (as opposed to hps):
They are both right in similar temps. The amount of ir in cmh is much less than in hps so you can run your cannopy at the same temps as a led cannopy 84ish F. This summer was scorching we had 30c(90ish Fiirc) at our cmh cannopy aand it turned out fine.

Op, you could even try a pure cmh side versus a pure ledside.. might be easier with hanging height

Again, im talking about 315s, no exp w 630s.

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315 are dope they can yield a lb each in the right setup one of my best grows was 3x315 nanolux cmh(not the most effecient) in a 3.5x8 I got 3lb. buds were growing into the hoods without getting burned that was a supersoil grow 18 plants 5 gal airpots. I yielded better with all led but the bud quality and uniformity was equal if not better with cmh people were begging me to sell them my personal stash from the cmh. If lived in a cold climate I would go 315cmh over led or probably a mix so I could shut of a cmh if it got hot. In the hot climate top of the line led are the best bet for long term savings. Par meter is pretty much a necessary tool if you grow with led setting light height a few inches off can make a big difference

Well, I got everything hung and installed. Without the air cooling i had on my hps, the room is hot! Hit 90's so I will have to come up with another way to cool it off, I will have to install a couple new intake fans that will blow room temp air in the room and see how it goes. Those CMH really pump off heat. After reading a bunch of logs I was worried about the temp being too low but this should be an easy fix to get it right.

Whats your rh? Once you get plants in there, transpiring, your rh will go up, whiich in turn lowers the heat a bit. Please read up on vpd which is important to know in order to get led plants drinking. Happy growing

Rocket Soul said:

Whats your rh? Once you get plants in there, transpiring, your rh will go up, whiich in turn lowers the heat a bit. Please read up on vpd which is important to know in order to get led plants drinking. Happy growing

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Its about 65% right now with nothing in the room, lights on. I will do some reading on vpd. Thank you for the reply.

kgp said:

Well, I got everything hung and installed. Without the air cooling i had on my hps, the room is hot! Hit 90's so I will have to come up with another way to cool it off, I will have to install a couple new intake fans that will blow room temp air in the room and see how it goes. Those CMH really pump off heat. After reading a bunch of logs I was worried about the temp being too low but this should be an easy fix to get it right.

Click to expand...

The old often dogged and under-rated air-cooled reflector

OneHitDone said:

The old often dogged and under-rated air-cooled reflector

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Man, you got that right. The old trued and tried method never fails. I am hoping chasing the the technology wasn't a mistake. If it was, I got plenty of supplemental lighting to play with.