hps or mh

diddystyles72

Well-Known Member
I've been using a 400 watt mh for my whole grow cycle veg and flowering what I want to know is will a hps be better for flowering and if so what will it make better on my harvest and I have been thinking of adding co2 to my set up but I heard that it not good at the end of the budding stage to use it and whats better the co2 bucket or the good old tank?
 

Brick Top

New Member
Metal halide puts out a better light spectrum for the vegging cycle and HPS puts out a better light spectrum for the flowering cycle.

Use a MH for veg and an HPS for flowering and your plants will get the best light spectrum for each cycle and they will grow more vigorously and you will have an increased yield …. As long as you don’t make errors along the way that will hurt your plants and therefore your yield.
 

diddystyles72

Well-Known Member
Metal halide puts out a better light spectrum for the vegging cycle and HPS puts out a better light spectrum for the flowering cycle.

Use a MH for veg and an HPS for flowering and your plants will get the best light spectrum for each cycle and they will grow more vigorously and you will have an increased yield …. As long as you don’t make errors along the way that will hurt your plants and therefore your yield.
do you use co2 in your grow?
 

lampshade

Well-Known Member
with hps you see about a 25% yield increase per watt from mh. Its hard to find a side by side grow, but if you pick up the new HIGH TIMES growers guide, there is an artical with a led vs mh vs hps. Mh yielded 10% less than UFO and hps yielded 15% better than UFO. Those numbers arnt accurate but very close (i can get the real numbers if need be). People have not really figured out why HPS yields more and it is of very hot debate. In my opinion it has something to do with phytochrome, but im not sure how. Also hps yeilds about 10-15% more light per watt than MH so some of it has to do with simply the amount of light. But that 10% extra, where does it come from... I dunno... Hopefully time will tell.
 

lampshade

Well-Known Member
Compared to MH yeah, but they are hella expensive 600 bucks for what is equal to a 400w, but you save money b/c they only use less than a 1/4 of the 400w mh or hps. In a year or two they will be the next big advancement, ohh and no heat. Mostly good for commercial growers who dont want to get busted by the eye in the sky.
 

M Blaze

Well-Known Member
I prefer HPS lights and I use them right throughout my grow from start to finish. I just add more light as it grows.
 

sativaplanet420

Well-Known Member
I was about to make the same post. I am going to experiment. I just got four 400 watt ballasts for either hps or mh. Does everyone here know you can buy a "warm spectrum" mh bulb? Very similar light to a hps, you know that red glow buds luv? The regular white/blue mh bulb is for veg.

What is another advantage of a mh bulb? Closer nodes, hps stretches plants out. To get your big harvest you water cool the bulbs (removing over 80 % of heat) and put the lights one inch from the top of the canopy. Too much light is bad, the perfect spectrum and perfect intensity is what you want. A wise gardener told me this method and I'm going to try it out.
 

M Blaze

Well-Known Member
Compared to MH yeah, but they are hella expensive 600 bucks for what is equal to a 400w, but you save money b/c they only use less than a 1/4 of the 400w mh or hps. In a year or two they will be the next big advancement, ohh and no heat.
Interesting, I like the sound of the 1/4 of of the running costs.
 

lampshade

Well-Known Member
In defense of MH they also produce slightly more UV rays. UV is what converts CBD to THC. Although compared to the sun MH or HPS doesn't have shit for UV.
 

Sure Shot

Well-Known Member
Well I pondered this same question untill.....

I found the new Super Blues from EyeHortilux. They are a dual arc bulb and consist of a 400w HPS and a 600w MH in the same bulb just srew into your HPS hood and your good to go.
 

lampshade

Well-Known Member
I second sure shot, just a couple days ago the mates at my shop were telling me about these exact bulbs.(and why i should buy some, lol).
 

sativaplanet420

Well-Known Member
Exactly the same. Hps puts out more lumens but in a different spectrum then mh. It depends on what ballast you use to determine energy costs.
 

RandyRocket

Well-Known Member
if possible i will put my 400 watt MH conversion bulb in the 430 watt hps if I don't have any plants in flower.

430 watt hps and some cfl's

400 mh
 

free2believe

Active Member
I found a little present at the second hand building supplies store. They had (2) 100 watt hps with fixtures and lightbulbs for $20.00 each and I also go a 400 Watt MH lamp with reflector fixture for $29.95 (and I got 10% off because I shop there often!) I have been using all 3 lights in my flowering room and am wondering... Can I use the 400 watt MH also with the 200 watt hps togther in my flowering room? I read some where that plant grow better when both blue and red spectrums were present during the life of the plant for stellar production. Will this hurt the flowering?

I think I might have my first boy. Maybe I will throw up some pics and you guys and say yeah or neah to the sex. Thanks
 

lampshade

Well-Known Member
I found a little present at the second hand building supplies store. They had (2) 100 watt hps with fixtures and lightbulbs for $20.00 each and I also go a 400 Watt MH lamp with reflector fixture for $29.95 (and I got 10% off because I shop there often!) I have been using all 3 lights in my flowering room and am wondering... Can I use the 400 watt MH also with the 200 watt hps togther in my flowering room? I read some where that plant grow better when both blue and red spectrums were present during the life of the plant for stellar production. Will this hurt the flowering?

I think I might have my first boy. Maybe I will throw up some pics and you guys and say yeah or neah to the sex. Thanks
Ed rosenthal (spelling?) actually recommends that you use 2 mh for every 1 hps, but today we believe its backwards 2 hps for 1 mh. A FULL SPECTRUM IS MUCH BETTER THAN JUST BLUE OR RED.
 
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