CMH or LED

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Indecisive

Indecisive

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Hello all! New grower here. Like many new users and growers I have lots of questions. I decided to register here because most of my google related questions lead me here, so I decided to join! I’ve read a few older threads but couldn’t find exactly what I was looking for. I know there are tons of variables that can/will affect each scenario. This is a multi part question so here it goes...

I am on the fence between 1x315 CMH and specifically a Mars-Hydro TSW 2000. The lights have about the same power draw. I will be growing indoors inside a 3x3x6 Tent. Grow medium will be soil This will be a stealth grow so I want to avoid as much noise as possible, i.e. heating/cooling or running of other machines

Mars-Hydro advertises about 2.3G/w. I’m now learning to take those numbers with a grain of salt. I initially decided on this LED because it wasn’t the traditional BLURPLE. And I wouldn’t have to worry too much about heat. Now I’m starting to think it won’t keep the tent warm enough. Has anyone had success with this light?



CMH -I’ve read lots of good things about this light. To start I would want to use a Phillips 3100k bulb.

Is there a significant difference between Vertical or Horizontal hanging bulbs?

Is there a significant difference between different systems such as the hoods and ballasts? I’ve seen some 315 CMH systems cost $400-$500 while others can cost $100-$200. Why is there such a difference in price, excluding the bulb.

Are the cheap $10 mechanical timers not suitable for CMH?

Is there a difference in performance with open hoods vs closed (with glass) hoods?

Do they produce enough heat to need supplemental cooling aside from an exhaust

Thanks in advance look forward to growing with you all
 
Kepp89

Kepp89

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if youre concerned about noise, you'll need one of the expensive exhaust fans that run quietly. my ac infinty one (the recent poplar one, it seems) is quite quiet but at 70% and higher its audible from all over the house when the house is otherwise quiet. tent is in the basement so maybe thats why?

when i had a small tent i couldnt keep temps above 70 with an led unless i added a heater. i now have a large tent and 3 cmh's keep the temp at around 78-80. requires an intake exhaust on the lowest setting (also ac infinty) to prevent going too high

i'm using a cheap timer, $9 and on my second grow and they've been fine. i'm using one timer for (3) 315 cmh's daisy chained and ran 24h lights on for a solid month.

the hoods/cost i believe boils down to how the light is reflected and whether or not you can change the unit from 315w down to 240 or 180 or whatever the settings are. i believe if i put a 240w light in my 315 it will have a real short life because too much power is being delivered to the bulb. one with a settings knob would switch the unit to 240w and the light would get proper power.

closed hood i imagine keeps the heat at the bulb instead of allowing it to free roam. if i'm right, these are the ones with 2 duct ports so you can exhaust that hot air directly out of the tent. if you want to heat your tent without a heater, then you dont want closed.
 
Formallyhap

Formallyhap

247
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the migro channel on youtube tests both and gives numbers regarding par etc.

CMHs are awesome but the led you mentioned is more efficient. Either one would be a good choice.
 
Indecisive

Indecisive

19
3
if youre concerned about noise, you'll need one of the expensive exhaust fans that run quietly. my ac infinty one (the recent poplar one, it seems) is quite quiet but at 70% and higher its audible from all over the house when the house is otherwise quiet. tent is in the basement so maybe thats why?

when i had a small tent i couldnt keep temps above 70 with an led unless i added a heater. i now have a large tent and 3 cmh's keep the temp at around 78-80. requires an intake exhaust on the lowest setting (also ac infinty) to prevent going too high

i'm using a cheap timer, $9 and on my second grow and they've been fine. i'm using one timer for (3) 315 cmh's daisy chained and ran 24h lights on for a solid month.

the hoods/cost i believe boils down to how the light is reflected and whether or not you can change the unit from 315w down to 240 or 180 or whatever the settings are. i believe if i put a 240w light in my 315 it will have a real short life because too much power is being delivered to the bulb. one with a settings knob would switch the unit to 240w and the light would get proper power.

closed hood i imagine keeps the heat at the bulb instead of allowing it to free roam. if i'm right, these are the ones with 2 duct ports so you can exhaust that hot air directly out of the tent. if you want to heat your tent without a heater, then you dont want closed.

AC infinity was one I was looking at. I was going to intentionally get a larger fan and add a controller to reduce speed but not sacrifice the needed airflow. There was another one I can’t quite recall that was advertising 24dba which seemed pretty low as well.

Considering CMH runs a lot cooler than other HID lights I don’t think I’ll do an open port hood to exhaust the I’ll want to use the heat.

I don’t think I’ll adjust the Watts so I won’t need a dimmable ballast. I was just going to adjust the height to about 30-40” during seeding. I’ll be doing autos to start.

Any info on Vertical vs horizontal hanging bulbs?
 
Kepp89

Kepp89

287
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oh i thought you were looking at LED and not HID? no matter to me though.

i have nothing on vertical vs horizontal but I THINK that again is affected by how it reflects the light around the area it covers.
 
Indecisive

Indecisive

19
3
oh i thought you were looking at LED and not HID? no matter to me though.

i have nothing on vertical vs horizontal but I THINK that again is affected by how it reflects the light around the area it covers.

I’m up in the air about CMH and the Mars Hydro LED. Can’t find enough grow info on the TSW 2000. And mixed user reviews with CMH. Some display insane results others mediocre or just ok.
 
DenzlFregren

DenzlFregren

39
18
If you are growing somewhere where you will want to increase temps the CMH is probably the better bet. If you are somewhere where you want to minimize temps rising I reccomend the LED. I get all 4 seasons and I use a cmh for about 5 of the coldest months and an led for the warmer ones. The tech is at the point where you can get great results with both. Now its just a matter of what fits your needs better.
Never have used mars hydro but with how many they have sold I believe it is atleast a good entry level light. Depending on your price point I may be able to point you somewhere else. But again Mae's hydro sells for a reason.
 
Anthem

Anthem

4,155
263
AC infinity was one I was looking at. I was going to intentionally get a larger fan and add a controller to reduce speed but not sacrifice the needed airflow. There was another one I can’t quite recall that was advertising 24dba which seemed pretty low as well.

Considering CMH runs a lot cooler than other HID lights I don’t think I’ll do an open port hood to exhaust the I’ll want to use the heat.

I don’t think I’ll adjust the Watts so I won’t need a dimmable ballast. I was just going to adjust the height to about 30-40” during seeding. I’ll be doing autos to start.

Any info on Vertical vs horizontal hanging bulbs?
You need to take vertical space into account when making your decision as well. I believe you said you have a 6' tall tent. Think about the height requirement the light needs to be away from the plant, the pot height, light dimensions, and any clear space requirements when making your decision.
 
Indecisive

Indecisive

19
3
If you are growing somewhere where you will want to increase temps the CMH is probably the better bet. If you are somewhere where you want to minimize temps rising I reccomend the LED. I get all 4 seasons and I use a cmh for about 5 of the coldest months and an led for the warmer ones. The tech is at the point where you can get great results with both. Now its just a matter of what fits your needs better.
Never have used mars hydro but with how many they have sold I believe it is atleast a good entry level light. Depending on your price point I may be able to point you somewhere else. But again Mae's hydro sells for a reason.

Great point. I think I may start of with the Mars Hydro. I get all 4 seasons as well and our winters get pretty cold. I may very well use both and pick up the CMH in the fall or winter. I know there are a ton better LEDs. I wanted to stay in the 200-300 range to start. I just like the positive reviews they’ve received. Thanks for the input
 
Indecisive

Indecisive

19
3
You need to take vertical space into account when making your decision as well. I believe you said you have a 6' tall tent. Think about the height requirement the light needs to be away from the plant, the pot height, light dimensions, and any clear space requirements when making your decision.

Im going to start with autos in 3-5 gallons pots. I don’t expect them to get too tall, but I think starting with the LED seems to be a bit safer considering it’s low profile and lower heat output. Thank you for your input
 
DenzlFregren

DenzlFregren

39
18
Great point. I think I may start of with the Mars Hydro. I get all 4 seasons as well and our winters get pretty cold. I may very well use both and pick up the CMH in the fall or winter. I know there are a ton better LEDs. I wanted to stay in the 200-300 range to start. I just like the positive reviews they’ve received. Thanks for the input
Glad i could help. Yeah if you get 4 seasons looking into both isn't a bad idea. The CMH saves me so much money in heating come winter it pays for itself immediately. And feel confident in mars hydro. Its definetly a solid light. Can grow some true fire when used in the right hands.
 
MarsHydroLED

MarsHydroLED

Premium Member
Supporter
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I’m up in the air about CMH and the Mars Hydro LED. Can’t find enough grow info on the TSW 2000. And mixed user reviews with CMH. Some display insane results others mediocre or just ok.
Thanks for your interest in Mars Hydro, the TSW2000 actual power is 300w and coverage is 3'x3' at bloom, it's good for your tent. And please noticed that the TS series average yields are 1.5g/w, not 2.3, check the details and real info on Mars Hydro official website: www.mars-hydro.com
You can check @khalt03 growing " Kim's Beginner Diary", it's in progress
Also, you can check the below thread the newest posts, 9 bruce banner whole growing under TSW2000 in a 3'x3' tent.
 
KLight03

KLight03

1,128
163
I’m up in the air about CMH and the Mars Hydro LED. Can’t find enough grow info on the TSW 2000. And mixed user reviews with CMH. Some display insane results others mediocre or just ok.
Personally, I have had no issues with my grow and it's my first. I started blindly, meaning I didn't have any working knowledge prior to getting here. I started with a MARS TS100, which is in my small tent now. The big tent is running a TSW 2000. Not one problem, no problems with heat. I think I will stick with Mars Hydro forever since I haven't been given any reason to not. I do have another light, but I had originally purchased it by mistake, but it works, just not as well and has too many directions, and I'm a salty retired medic who likes to assess on approach and purple lights don't do it for me. Let me know if you have any questions, I'm happy to help.
 
IMG 20200317 135025
SwoleGrow

SwoleGrow

397
63
AC infinity was one I was looking at. I was going to intentionally get a larger fan and add a controller to reduce speed but not sacrifice the needed airflow. There was another one I can’t quite recall that was advertising 24dba which seemed pretty low as well.

Considering CMH runs a lot cooler than other HID lights I don’t think I’ll do an open port hood to exhaust the I’ll want to use the heat.

I don’t think I’ll adjust the Watts so I won’t need a dimmable ballast. I was just going to adjust the height to about 30-40” during seeding. I’ll be doing autos to start.

Any info on Vertical vs horizontal hanging bulbs?
I run 2 sun system lec boss in my sealed/insulated 8x8 room I built inside my “uninsulated” garage. During the recent cold months I never turned on my polonis heater, even during lights out. I also have the ac infinity 8” with a phresh filter(no silencer) and I forget it’s even in there when I’m sitting a foot away from it. In the beginning I started my lights at 50% and upped the intensity 10% each day to reach 100%, don’t ask me why ( I’m a noob) but I thought it would be good for the seedlings. Other than that I’ve only adjusted height. I’m on day 7 from flip.
 

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