Adding cmh to an already 4/1000w hps grow room

So as in the title says I'm running 4-1000 hps lights in a roughly 637 sq. foot room. At the moment 2 lights are in 6in raptor hoods, (though they're not air cooled) and the other 2 are in large adjust wing open hoods. I'm running a sealed room with co2 and a 24k btu daikin mini split. So at that rate I'm running 6000btus per 1k hps(cali rules). I was thinking of adding a dual bulb/ hood 630 cmh to the middle of room. Obviously my mini split will have to work a lil harder but I would think a 24k btu mini split could handle 4,630 watts of HID lights, correct? Any thoughts would be greatly appreciated. O and my 4- 1k ballast are mounted outside of grow room.

Oh wow, you have 2 1kw'ers running without cool tubes? :O My lord I bet that gets pretty hot...anyhow, back on point lol. I would think that the mini split would be capable of handling the extra wattage, though I've never used anything but for a window ac unit so I'm by no means an authority. I just added 2x 315's to my 1kw grow space and I am so happy I did, the extra light is great. What canopy temps are you running as of now?...If you're not struggling to control temps as is, I think you'll be ok.

Logan Burke said:

Oh wow, you have 2 1kw'ers running without cool tubes? :O My lord I bet that gets pretty hot...anyhow, back on point lol. I would think that the mini split would be capable of handling the extra wattage, though I've never used anything but for a window ac unit so I'm by no means an authority. I just added 2x 315's to my 1kw grow space and I am so happy I did, the extra light is great. What canopy temps are you running as of now?...If you're not struggling to control temps as is, I think you'll be ok.

Click to expand...

Dude I have a 24,000 btu mini split. I could run 4-1000s all in a open hoods-no problem, no cool tube needed. Can keep canopy at whatever temp I desire in the 70s. I usually keep it between 73 and 75F. I'm just wondering if 630 cmh would be a little to much but I think I would be good but it would tax my ac and it would being working harder than it is now. I think I'm ditching the last 2 raptors and going to run all 4 lights in the large adjustawings. I just don't like how the raptors spread the light compared to the adjustawings. With all 4 hps in the large adjustawing reflectors I actually might not need the cmh in my space, they are awesome reflectors in the right situations.

My two cents; having tried this very thing, I discovered that my plants REALLY preferred the CMH spectrum, to the point where mixing the two resulted in worse outcomes than just HPS alone.

It was a surprising finding. YMMV

Well FWIW I have 4 ton units and they each cool 10,800 watts

6 x 1kW DE HPS running at 120%
6 x 400 watt HPS
2 x 600 watt HPS

ttystikk said:

My two cents; having tried this very thing, I discovered that my plants REALLY preferred the CMH spectrum, to the point where mixing the two resulted in worse outcomes than just HPS alone.

It was a surprising finding. YMMV

Click to expand...

That's interesting. I will get cmh lights down the line for another grow. I didn't think mixing the spectrum would get not so great results, but good to know.

Hi @Dividedsky You seem to have a very professional setup, I like that
If your A/C can handle 4- 1000w HPS lamps, adding that 630w CMH should be okay.

Do you run your lamps at night? If not, this would hep lower the temps by 6 or 7F at least.
Also, using a light-mover can help spread the heat and at the same time, reduce the number of lamps required.

That CMH can definitely help the plants stretch a bit less, especially Sativas.. And make the buds a bit denser.

Best of luck to you

Al,

Aladdin.khalifa said:

Hi @Dividedsky You seem to have a very professional setup, I like that
If your A/C can handle 4- 1000w HPS lamps, adding that 630w CMH should be okay.

Do you run your lamps at night? If not, this would hep lower the temps by 6 or 7F at least.
Also, using a light-mover can help spread the heat and at the same time, reduce the number of lamps required.

That CMH can definitely help the plants stretch a bit less, especially Sativas.. And make the buds a bit denser.

Best of luck to you

Al,

Click to expand...

Yes aladdin, I run them at night..lights turn on at 5pm. I don't have light movers. I do mix the spectrum a bit, I have a 1000w MH bulb in one of the hoods to mix things up a bit for newer plants going into flower room. I have had great results. I'm chopping my 1st plant down today since updating my grow room. Will post some pics later.

Renfro said:

Well FWIW I have 4 ton units and they each cool 10,800 watts

6 x 1kW DE HPS running at 120%
6 x 400 watt HPS
2 x 600 watt HPS

Click to expand...

So doing the math off the top of my head that works out to around 4500btus per each 1000w of HID, am I in the right area, Renfro? I have to check out your grow thread, haven't peaked at it in a while, how are things going man? Yours is one of the best setups I've seen in a while on this site. I like how you keep your grow room clean, that's how I am. Growing is great for people who are neat and have ocd tendencies with their cleanliness. Lol.
Obviously the Cali rules- 6000/btus per ea 1000w of hid doesn't apply to every situation. There are so many factors- sealed room, A/C hoods, co2, dehus, fans, ect. I would say when thinking of getting a mini split you always want to get 4000btu units and above for every 1000w of HID. Factors like having a sealed room, well your going to want to go a lil higher. Love my mini split though, its a game changer, wish I got it years ago.

ttystikk said:

My two cents; having tried this very thing, I discovered that my plants REALLY preferred the CMH spectrum, to the point where mixing the two resulted in worse outcomes than just HPS alone.

It was a surprising finding. YMMV

Click to expand...

I must say, this has me perplexed. I would think that giving any significant amount more of light would have only good affects, unless you're already providing all the light they can absorb or are at the limit of your cooling capabilities....I've added 2x315's to my 1kw HPS and have had great results so far.

I think the "cali rules" work well when you have solar heat loads, since I run in a basement thats pretty much not a factor.

Logan Burke said:

I must say, this has me perplexed. I would think that giving any significant amount more of light would have only good affects

Click to expand...

I agree with ya, I was a bit perplexed by that response. Figured mixing a cmh with hps would be great.

Renfro said:

I think the "cali rules" work well when you have solar heat loads, since I run in a basement thats pretty much not a factor.

Click to expand...

Haha ya for sure. I remember someone using that phrase "cali rules" for amount of 6k btus per 1k of HID. Always stuck with me. Also doesn't really apply to me seeing as I'm growing in a basement in New England. Its a good guideline though.

Dividedsky said:

That's interesting. I will get cmh lights down the line for another grow. I didn't think mixing the spectrum would get not so great results, but good to know.

Click to expand...

I'm still a bit mystified about the outcome of that test. The only thing I can come up with is the difference in IR/far red between the two having something to do with it.

CMH runs kicked ass and brought the frost.

Dividedsky said:

Yes aladdin, I run them at night..lights turn on at 5pm. I don't have light movers. I do mix the spectrum a bit, I have a 1000w MH bulb in one of the hoods to mix things up a bit for newer plants going into flower room. I have had great results. I'm chopping my 1st plant down today since updating my grow room. Will post some pics later.

Click to expand...

I run my lamps from 11pm to 11am. If you're in 12/12 all the time, I think it's the coldest period as a house traps heat and it takes a few hours before the temps start going down.

A light mover would definitely help you manage the heat.

Right on, It's awesome to mix the spectrum.

Best,
Al

I do the exact same thing Aladdin! Except I run mine from 5pm to 5am simply due to my schedule, and I have to tend to them daily because I do hydroponics. Running at night time is one of the smartest moves I've ever made in growing!

Aladdin.khalifa said:

I run my lamps from 11pm to 11am.
Best,
Al

Click to expand...

Wow 11pm, that's late dude. I would not want to wait till 11pm to get into garden to water check things out, ect. Use to have them going at 8pm to 8am and thought that was late, lol.