CMH question 4x8 grow tent
- Thread starter KK4IEM
- Start date
Lordhooha
Well-Known Member
3- 315 would be fine
Flowki
Well-Known Member
Assuming you were doing a scrog or similar type grow you are falling well short of 30W per square foot with 3x fixtures. The 630's will get you over 30wpf but you will be hanging the lights a lot higher and that may lose intensity, tent or not.
If you could use 4x 315 fixtures the light will be closer, better spread and waste less as a result. It does mean you will be using 200w more over the hps but you are also using a bigger space and that should be taken into account. However 4x is a bit too wide for 315 imo but with some well planned over lap and being in a tent your outside edges should not suffer too much. Try and use hoods with a wider angle to cast out to the edges, so that you don't have to raise the fixtures too high in order to cover the print.
Hugo Phurst
Well-Known Member
I've just ordered 2 more CHM last night, so my 4x8 (flowering) tent will have 3x315w CMH (2x300k & 1x4100K), that should be adequate (I think).
be4meliz
Well-Known Member
3- 315 watt lights in 4 by 8(same setup I have) would = 29.5 watts per sq. ft., so not that far off. I agree that one more would give better coverage, but this setup works on 6 plants if spaced correctly.
Greenhouse;save
Well-Known Member
It's a bit daft ......4lights in a 8×4 tent.......why not just go 2 600w hps like most folk do......
rocko pumper
Well-Known Member
Definitely put an hps in there you can't beat the multi spectrums or just forget both and go with hlg -550 leds maybe 2
Flowki
Well-Known Member
@KK4IEM
Oh you're right sorry, I miss calculated. 3 cmh will be good. Just keep in mind OP you're using less than 1000W, for all you will cover more space you will cover it with less depth that you will be use to with the single 1000w. In other words don't expect miracles out of 3 fixtures, it ''should'' yield the same as you're use to or more while the quality will increase. It's why I assume a loose scrog type of style as even tops will make the most of the spread. If you want to get more technical allow the most outer edge tops to get taller and take advantage of some side lighting, depending on hood type.
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Flowki
Well-Known Member
More lights of lower W are better than big high W lights, cmh also has a better spectrum/efficiency. I am not aware that ''most folk'' indoor use hps other than those starting out or those who don't believe in newer tech.
Greenhouse;save
Well-Known Member
Wipe your mouth pal........your dribbling. .........bigger watt with full spectrum. ..e.g..1000w gavita blows ANYTHING cmh completely to bits.........and as far as not embracing newer tech goes.........I've probably got newer tech than you....,!
Flowki
Well-Known Member
As far as I've ever read that isn't true, but correct me, Im not afraid of being wrong. What scenario do you apply this too?.
The gavita is in a 4x4?.
3x315 to cover a 3x8.
The 315's have slightly less watt and less penetration but can cover more canopy. How much dooes the 1k (%value is fine) blow the cmh to bits in weight and/or quality?. How do the efficiency, heat management and bulb lives factor in after that. Btw If the 1k footprint is 5x5 the bulb will be higher to gain cover and thus lower over all intensity, 6 and 2 3's, like trying to stretch the 315's out to 4x8.
Embracing newer tech was a broad statement, you deliberately took it personal in order to tell me your penis measurement. I've made a note none the less ;p.
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