600 HPS,1000 HPS or 315 CMH for a 4x4?

newguy123 said:

I forgot to mention that I will be using a 3x3 tent after reconsideration

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I am just about to try my sun system 315 LEC remote reflector and galaxy ballast for vegging in a 3x3.

Should work great!

Eventually I will run a full cycle with it. But I have a perpetual garden to keep running.

I built a dedicated flower room out of my spare bedroom and ditched the flower tents for more open space.

MichiganMedGrower said:

I am just about to try my sun system 315 LEC remote reflector and galaxy ballast for vegging in a 3x3.

Should work great!

Eventually I will run a full cycle with it. But I have a perpetual garden to keep running.

I built a dedicated flower room out of my spare bedroom and ditched the flower tents for more open space.

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that's how i roll

i built a hidden, lockable room in my basement on its own circuit, room is 12x10, a closet on one side that is 7ft long 3ft deep ceiling height in room is 7 ft w/ sliding doors just like a reg closet,light proof veg area.. outside the closet is a 9x10 ft area for my flowering w/ a 4x6ft f&d table so i have just enough room to get around the table..before this i grew in my garage, i built a computer room fully air conditioned,, when i sold the house w/ lights taken out u couldnt know it was a grow room,, just wpondered why someone would put a computer room in the garage..lol.. i then bought a bc northern lights bloombox and mothership 7 thousand bucks,,but paid itself off in 2 harvests, im gonna sell them now,, hope i can get 5g only 3 years old still under warenty w/ 24 hour customer service the people there are really nice and knowledgable.. had i known i was going to buy a new house and build a room i never wouldve bought them but i simply need to be growing,, cant live happily w/ out my grow,, i talk to my plants,, my grow room is my man cave away from wife n kid,, plants listen and dont talk back,, better than any wife.lol

Ok, I think I read a bunch about the 315's but was wondering if anyone ran a compare for vegging clones. I run a 600 MH for 4 weeks then throw my bought clones into flower, leave the MH for two more weeks then go to 600 HPS. Will the clones grow as fast or nice with the 315's? Anyone tried?

For just veg yes. For flower I would say a 315 is like a Blue MH with less penetration down low on taller plants. The 600 Watt Blue MH is still my favorite light to use of all I have tried. Just my opinion and $0.02

Evil-Mobo said:

For just veg yes. For flower I would say a 315 is like a Blue MH with less penetration down low on taller plants. The 600 Watt Blue MH is still my favorite light to use of all I have tried. Just my opinion and $0.02

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Just wanted to say. I am really liking the 600 Blue with the 600 Super hps in my 7' x 3'-4' flowering area.

Mrs. MMG agreed the complexity and flavor may be a bit better than hps alone. Also the lowers concern me but the last plant says again that genetics take a big part in the dense lowers.

Most growers just cut them out early anyway it seems. I can't afford to with my space though.

So I may actually go back to 2 hps to see for a couple cycles but I just keep liking that natural light in there like the cmh had.

The 315 is going in the 3x3 tent for vegging. High hopes for faster vegging plants than my t-5's. And maybe stouter but I am a stickler for keeping in optimum light parameters so they all seem to work well honestly.

Buba Blend said:

Depends on your level of experience.
If a new grower or someone with a few grows under his belt uses 600W hps he will likely get a smaller yield of a higher quality weed versus the 1000W hps where he may get a bigger yield but quality can suffer to various degrees. Also with more problems likely to arise from the bigger plants higher demands your yield may end up worse than the 600W yield.
An experienced grower using 1000W can shrink this gap to almost getting the same quality as an experienced grower using a 600W hps. Some may say that they use 1000W and get the same quality as those using 600W. Might be true who knows.

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WTF are you taking about? The only difference between a 600 and a 1000 is the sq ft they cover and the penetration into the canopy. The 1000 covers more and penetrates deeper.

If someone knows WTF they're doing, a 1000 will blow away a 600 in yield, every time. Quality isn't going to change because of more/ less wattage.
I run a 1000 in one 4.5x4.5 tent, 2 600s in the other. I'll be ditching the 600s for a single 1000 soon. Same coverage but I can grow 4 ft plants under a 1000. 600s are great if you don't have the height to run the 1000, which is how I started and why I have them.

MichiganMedGrower said:

Just wanted to say. I am really liking the 600 Blue with the 600 Super hps in my 7' x 3'-4' flowering area.

Mrs. MMG agreed the complexity and flavor may be a bit better than hps alone. Also the lowers concern me but the last plant says again that genetics take a big part in the dense lowers.

Most growers just cut them out early anyway it seems. I can't afford to with my space though.

So I may actually go back to 2 hps to see for a couple cycles but I just keep liking that natural light in there like the cmh had.

The 315 is going in the 3x3 tent for vegging. High hopes for faster vegging plants than my t-5's. And maybe stouter but I am a stickler for keeping in optimum light parameters so they all seem to work well honestly.

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I took my CMH down this run, i didn't like how larfy it made my buds compared to my hps, i think i need the 3k bulb and a vertical reflector if i plan to use this again.

in veg the 3100k 315 watt cdl grows plants shorter and more nodes per height than a 400 watt 6500k mh... also using mh in veg then hps in flower nearly tripples the stretch o0f plants vegged w a 3100k 315 then flowered under 3100 k 315 cdl's... a plant that veg's and flowered under the cdl will only double its height..

TheChemist77 said:

in veg the 3100k 315 watt cdl grows plants shorter and more nodes per height than a 400 watt 6500k mh... also using mh in veg then hps in flower nearly tripples the stretch o0f plants vegged w a 3100k 315 then flowered under 3100 k 315 cdl's... a plant that veg's and flowered under the cdl will only double its height..

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What type of reflector do you use? Got any bud pictures?

TheChemist77 said:

in veg the 3100k 315 watt cdl grows plants shorter and more nodes per height than a 400 watt 6500k mh... also using mh in veg then hps in flower nearly tripples the stretch o0f plants vegged w a 3100k 315 then flowered under 3100 k 315 cdl's... a plant that veg's and flowered under the cdl will only double its height..

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The 315 in my flower room definitely helped keep my plants shorter. It also made my yield go down almost 30% on average with my bushes in the process. And I only try to flower 2' thick of canopy.

I am not having that problem with a 600 mh and a 600 hps in there now.

My 315 is going to veg. I will only use them as supplemental spectrum likely from now on.

I think 2 per 4x4 would be necessary for better results than a 600 w bulb.

newguy123 said:

Hey guys, I am planning my next grow and I am wondering what is the preferred light for a 4x4 tent. I have the choice between 600HPS, 1000 HPS and 315CMH. Thanks!

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im running a 4x4 right now with a 1000w and the summer heat isnt helping since i have no ac in my garage. just keep a eye on the heat unless u have a dimmable ballast.

all my cdl's are from boulderlamp.com.. the ballast is on top the reflector i paid 500 a piece,, if i could go back i wouldve got sun systems, i hear good things about them.. but i am very happy w/ the boulder lamps,, i dont know how somebody can lose yield w/ cdl's.. i never got much better than 1 gram per watt w/ hps, mh or both..with cdl's i hit 1.4 gpw on my first run,, ive heard people claim u can get 2 gram per watt w/ cdl,,, i think that is bull i have topped off at 1.56- 1.6 gpw, now im sure there are much better growers than me,, but my opinion is 2 gpw is unachievable w/ any light exept the sun...

TheChemist77 said:

all my cdl's are from boulderlamp.com.. the ballast is on top the reflector i paid 500 a piece,, if i could go back i wouldve got sun systems, i hear good things about them.. but i am very happy w/ the boulder lamps,, i dont know how somebody can lose yield w/ cdl's.. i never got much better than 1 gram per watt w/ hps, mh or both..with cdl's i hit 1.4 gpw on my first run,, ive heard people claim u can get 2 gram per watt w/ cdl,,, i think that is bull i have topped off at 1.56- 1.6 gpw, now im sure there are much better growers than me,, but my opinion is 2 gpw is unachievable w/ any light exept the sun...

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I run 2 at 600 watt but veg under a single 600 MH, get at best .75 gram per watt, but 600 watts vs 315 per watt, so you are saying that with 2 - 315w cdl's i should be able to produce double what my 600 HPS does, wow, I know I dont grow as well as some but that’s amazing to me, are you doing Hydro?

TheChemist77 said:

all my cdl's are from boulderlamp.com.. the ballast is on top the reflector i paid 500 a piece,, if i could go back i wouldve got sun systems, i hear good things about them.. but i am very happy w/ the boulder lamps,, i dont know how somebody can lose yield w/ cdl's.. i never got much better than 1 gram per watt w/ hps, mh or both..with cdl's i hit 1.4 gpw on my first run,, ive heard people claim u can get 2 gram per watt w/ cdl,,, i think that is bull i have topped off at 1.56- 1.6 gpw, now im sure there are much better growers than me,, but my opinion is 2 gpw is unachievable w/ any light exept the sun...

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Yeah but 1.5 grams per watt with a 315 light is about 450 grams, whereas 1 gram per watt with the 600w hps is 600 grams, so that's a huge decrease in yield unless you are using equal watts (two 315's per 600w hps).

I just personally feel that the CMH has a great spectrum but doesn't have great intensity, it's only putting out 33k lumens vs a 600w hps bulb at 90k lumens. Spectrum does make a difference , but the intensity difference is so vast i just don't see myself taking down my 600w hps for a single 315 CMH. I think these are best for replacing a 400w hps.

hippy132 said:

I run 2 at 600 watt but veg under a single 600 MH, get at best .75 gram per watt, but 600 watts vs 315 per watt, so you are saying that with 2 - 315w cdl's i should be able to produce double what my 600 HPS does, wow, I know I dont grow as well as some but that’s amazing to me, are you doing Hydro?

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yes im in hydro, i use rock wool 4x4x3 inch blocks a 4ftx6ft f &d table w/ a 50 gallon rez, i use gh maxi series nutes,, table covered by 2 315 watt cdl's,, a beginnjer can probably hit 1.4 gpw with the 315 watt ceramics.. i havnt updated my grow in a wile,, but u can check it out at

https://www.rollitup.org/t/chemist77-315-watt-cdl-grow.880895/page-13

Yodaweed said:

Yeah but 1.5 grams per watt with a 315 light is about 450 grams, whereas 1 gram per watt with the 600w hps is 600 grams, so that's a huge decrease in yield unless you are using equal watts (two 315's per 600w hps).

I just personally feel that the CMH has a great spectrum but doesn't have great intensity, it's only putting out 33k lumens vs a 600w hps bulb at 90k lumens. Spectrum does make a difference , but the intensity difference is so vast i just don't see myself taking down my 600w hps for a single 315 CMH. I think these are best for replacing a 400w hps.

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IIRC, the 400w produces 60k?

From the specs and what I've seen done with them I couldn't spend that much money when I can get a 400w adjustable digital ballast for half the cost.

Enigma said:

IIRC, the 400w produces 60k?

From the specs and what I've seen done with them I couldn't spend that much money when I can get a 400w adjustable digital ballast for half the cost.

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I ran a 315 CMH in between my two 600w hps this last run, it worked well, but honestly i wish i just used my 3rd 600w hps, the yields would have been better.

1 600 watt hps= 600 grams,, 2 315 watt cdls (630 watts)= 800 grams wroughly.. that extra 30 watts gets u 200 grams...
yes 1 600 watt hps will yield more than 1 315 watt cdl, but 1 315 watt cdl still gets you more grams per watt more gpw = efficiency ...
i do agree going from 1 600 to a single 315 is just plain stupid, regardless of gpw or efficiency.. your giving up 200 grams.. however putting 2 315's in place of the single 600 watt hps,, your only using 30 more watts, youll also save on heat issues as 2 315's putt out less heat than a single 600 watt hps and you are increasing your gpw by idk 20-25%.. id get 2 315's over a single 600 watt hps and 3 315's insted of 2 600 watt hps...

Yodaweed said:

Yeah but 1.5 grams per watt with a 315 light is about 450 grams, whereas 1 gram per watt with the 600w hps is 600 grams, so that's a huge decrease in yield unless you are using equal watts (two 315's per 600w hps).

I just personally feel that the CMH has a great spectrum but doesn't have great intensity, it's only putting out 33k lumens vs a 600w hps bulb at 90k lumens. Spectrum does make a difference , but the intensity difference is so vast i just don't see myself taking down my 600w hps for a single 315 CMH. I think these are best for replacing a 400w hps.

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Glad you did the math for him.