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New grow tent, need help to choose new light: LED or CMH?

R

rastafari80

Hi guys,

Please, I really need some opinions and suggestions about my new light.

I have a new 3x3 grow tent, since my old 2x2 was really worn-out.
I used mainly a 250w mh/hps but it's not enough to cover a 3x3.

My main choices are these two:

- Mars Hydro II PRO Epistar 120 600w: it looks like a good led light, anyway I'm not sure if it's enough to cover the tent. Not really sure about the noise and the fact it doesn't produce heat: sometimes the heat it's helpful to manage temperatures.

- Lumatek CMH 315w kit with a 3100k bulb for the full run [I do a short vegetative stage, or at least I can use the 250w MH for the veg].
It's noiseless and perfect for a 3x3 tent.
Anyway I can't understand if you can run it ay 25/50/75% of the power without damaging the bulb and if the closed reflector needs an air extraction like for the cool tubes.

I'm not considering HPS/MH anyome because I don't want to consume 400w or more.

ANY considerations or suggestions will be very very helpful!

thank you guys :huggg:
 
G

Guest

I can't answer specifics on the questions you posed, but I am able to get about a pound out of a 3x3 with a vertically hung 315CMH. I grow vertically, but had an open reflector with a fan blowing up toward the bulb. I vented the whole tent with an inline fan 24/7. I really liked that set-up and think that you could be very happy.
I am going to get a 39"x39" (100cm x 100cm) tent and see how the extra 20sq foot do with either a 315CMH, or a horticulture lighting group 260W QB V2 LED KIT.
On the fence as to what I'm gonna do as LED is new territory for me.
Best of luck with your choices!
 

Lost in a SOG

GrassSnakeGenetics
You'll regret the mars hydro Imo, I got an advanced p300 which is a fancy mars led and still sent it back,, 3 month no quibble returns on the advanced though if you want to see blurple.. Massive waste of watts for nothing, poor penetration and a backwards approach to horticulture lighting Imo.. Id say it was hard to decide if cfls wouldn't have been better at the time.. A 600w led sounds like a joke, made with proper high bin leds, 600w of light should cover more like 8 square feet..

The horticulture lighting group boards pack real punch for your money.. Ive got cobs as well but don't feel the return justifies how hot they get..

The HLG lights will shave degrees of your heat, save you considerably on wattage and if kept at the right distance can produce much better nugs..

But If that's your options get the cmh and air cool it Imo.. My philosophy is to always buy from a company with a reputation to lose, then they'll more than likely sort you out if anything happens, not some Chinese snakeoilsman..

You can easily beat a 315 cmh with less watts of led.. Especially with correct spread and distance..

Also if you're interested diy led lights check out Solstrips, I made a rig for this last grow and the (air cooled) cmh wouldn't do better using 60 watts more than I'm running the Solstrips at..:2cents:
 
R

rastafari80

thank you so much guys, I know it's an old debate but you helped me to clear my mind.

The horticulture lighting group boards pack real punch for your money.. Ive got cobs as well but don't feel the return justifies how hot they get..

The HLG lights will shave degrees of your heat, save you considerably on wattage and if kept at the right distance can produce much better nugs..



Lost in a Sog: the p300 was my first choice but it's quite expensive... and it's consider on of the best led lamp in the market..
HLG looks very good but I honestly don't know which one to choose and it's best for a 90cmx90cm tent... any suggestion? Not sure if these products are "discreetly" available here... anyway it worth a try
 
What a lot of guys are doing with screw in led lights (SIL) is really impressive. Bulbs are easy to source and are not conspicuous. Ive considered 315w cmh extensively for a space about that size, but i keep coming back to the SILs and doing it diy. Check out the stickies in the micro grow forum. Blynx has some examples that seem hard to beat.

Solstrips look interesting too but the SILs are so easy to replace and easy to play with spectrum.
 
R

rastafari80

thanks, I'll read about SIL... how many [considering wattage] would you use?
 

ronbo51

Member
Veteran
as mentioned go to the micro section in grow diaries and check out the off the shelf led thread. 30 watts / sq ft. is giving great results. 8- 14 watts per bulb actual draw, not "equivalent". Pry the plastic lens off and grow.
 
R

rastafari80

hi guys, I choosed a CMH light at the end. I think, right now, it's the best option for the wattage consumption, noise and for having some heat [yes, I need some heat when it's cold]
the lumatek dimmable ballast looks great, it's dimmable and this makes it very usefull during veg staging.
thank you everybody for opinions & suggestions!
 

Klompen

Active member
Man I sure hate how LED suppliers are generally not honest about wattage. Not only do they often sell lights as "600W" or whatever while saying "actual wattage is 300W", but then if you take a wattage meter to them(or calculate it with a multimeter manually) you find out they actually draw 270W or something like that. It drives me CRAZY. I'll be in the hardware store looking at lights and I will see 10 different "60W" LED bulbs that have 10 different actual wattage ratings and 10 different lumen output ratings(half of which are probably inaccurate). LED is clearly the future, and I LOVE my Phillips Mastercolor Retrowhite 400W CMH, but the LED business pisses me off.
 
R

rastafari80

@komplen I totally agree with you, the LED market is very "dirty" about specs and actual results. that's why I choose the CMH.
the comparisons to hid in most cases are meaningless.
I'm not sure if it's the future for a simple reason: the real consumption for a good led light system, maybe a qb or cobs, isn't that far from hps/cmh. Even the heating factor is debated and, if anyone is going to study the BTU per watt formula will get very surprised.
 

Sport Farmer

Active member
Veteran
I know it's probably not the most popular option around here, but have you considered making your own? That's what I did and I have never been happier with my lighting setup. Cheap to make, easy to swap bulbs out, super low heat, low power usage, better coverage of tent in my opinion, more space inside (light able to get higher), easily adjustable with jack chain and hooks. Doesnt weigh very much in total.

Consider making long strips with 4-5 regular old LED bulb outlets per strip and 4 strips total and then space those out in your tent.... I've added another strip since this pic below, but this is what I am talking about in terms of DIY lighting rig.

picture.php


Just another option I suppose but thought I'd throw it out there!
 

Klompen

Active member
I love CMH don't get me wrong, but in a general sense as far as lighting is concerned LED is definitely the future. The main issue at hand is that CMH represents the pinnacle of a long time line of HID development, whereas LED is newer technology and is likely nowhere near its pinnacle. As far as growing specifically goes, CMH definitely holds a solid place. LED has a big edge though when it comes to distribution of the light. HID is very point-source. Of course the sun is very point source, but it is so far away that the angle of incidence is much shallower across a given space. If you could put your CMH a few million miles out that might be a more similar comparison lol....
 

Iamnumber

Active member
Thanks for sharing Sport farmer.. looks nice :)


OP, I please do post review on your new light once you get a good feel about it and its performance.. please do include info on your old light setup as I assume that will be your point of comparison.
 

FinalBoss

New member
I have a phantom 315 cmh in a 3x3 tent. Imo it's the perfect light for that size. Low heat, excellent light distribution in a 3 by 3 area. That's the size that a 315 is meant to be in. My first ever grow in that size of a tag gave me over 12 oz of White Widow. Keep in mind it was my first grow and I could have gotten lucky but chances are it will only improve
 

Rush_in

New member
I'm totally new to growing, I went to a few hydro shops in my area to get some information on lights.... a local hydro store recommended a 315w CMH with a 4200k bulb, said I could veg and flower with this light (whats your opinion?)....it's for a cabinet I built thats 3x4x6'...I live in a cold climate and worry about how cold it can get at lights out....I imagine theres heat coming from the light but I expect I'll need a heater in the room (I'm yet to build in garden shed) I've got a 4" in-line fan and carbon scrubber....it's necessary to eliminate all odors, don't want to annoy the neighbors....your tent size is about my cab size, seems this light makes sense for my attempt (your opinion?)....What if anything would you do differently on your next grow?
 

zachrockbadenof

Well-known member
Veteran
I have a phantom 315 cmh in a 3x3 tent. Imo it's the perfect light for that size. Low heat, excellent light distribution in a 3 by 3 area. That's the size that a 315 is meant to be in. My first ever grow in that size of a tag gave me over 12 oz of White Widow. Keep in mind it was my first grow and I could have gotten lucky but chances are it will only improve

my tent is 4x3.5ft - last grow i had 2x315's and i thought the light was insuff... adding a couple of 300w 'cheap' led's this time around - last grow tried adding a 4ft 8bulb fluor... WAYYYY toooo much heat .... burnt the ladies
 
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