Is a 400w MH really better than a 4-8 T5-HO bulbs for veg?

doniboy

Well-Known Member
Long story short, I'm a newbie looking into lights for my mother/clone veg room. I narrowed my options down to a T5 fluorescent or a 400w Metal Halide light setup. I started to do research on the pros and cons of both. The gist so far is that the "MH will produce a shorter, stockier plant, though, and less space between leaves on the stem" and "MH will produce more healthy looking plants with tight nods" and "MH will produce higher THC" than using T5 lights. I feel that most people are just regurgitating what they've been told and/or repping the ONLY setup they've ever tried.

I want to know the why and how MHs are better than T5s? I'm a nub, but to me, they do not seem to be..


  • T5 fixtures last longer than a ballast.
  • T5 bulbs last longer than MH bulbs, AND cost A LOT less to replace.
  • T5 spreads light more evenly than MH
  • T5 are more efficient than MH setups.
  • T5 are simple, uncomplicated, have less components (no ballast, cool hood, ducting, etc), weigh less, and cost less in maintenance cost and replacement cost over in general.
  • A Metal Halide Bulb 400W bulb produces about 29,000 Initial Lumens, but the amount of light these bulbs emit decreases big time with time. Basically after a few months of use, a 29,000 lum rated bulb isn't actually emitting 29,000 lumens anymore...
  • We all know the amount of light decreases rapidly within only a few inches of distance, so taking into account that T5 can be positioned closer to plants than MH and that the T5 doesn't need to be incased in some kind of glass air cooling fixture (which blocks even more light), I think that should even the lumen gap even more between the T5 and MH bulbs, no?
  • A blue spectrum T5-HO bulb has 6,500 approximately. lums per bulb and it's my understanding that you can fix up to 8 tube in a 4" fixture within a 4x4 tent. If I go with a 6 tube fixture , that would be 39,000 lums correct? (6,500 * 6 = 39,000) Without the air cool hood glass and with being closer to the plant, wouldn't this be more light than using a 400 MH lamp?



What's missing in my equation? I'm trying to understand why there's so much hype, and why just about EVERYONE is saying MH is the best way to go when to me it seems like the most pragmatic, expensive, and least efficient compared to high output fluorescent lighting...
 

doniboy

Well-Known Member
its all about intensity and how t5's dont have it.
Like everyone else, you made a statement without explaining how or why they do not. If a 6 tube T5 fixture is putting out more lumens, can be placed closer, don't loser intensity over time, and aren't encased in glass, how do you figure they don't have the "intensity?"
 

PurpleBuz

Well-Known Member
For vegging it really doesn't matter. Multiple T5 HO units with a good spectrum will do as well as MH, and will provide more flexibility.
You can start with smaller units like a 2' 4 bulb unit for seedlings, add another as they grow up a bit and finally add a 4' 4 bulb unit as they get wider.
Thats only a total of 3 units about the same wattage as a 400 MH, but you didn't have to power it all up until the plants get some size.
 

mrwood

Well-Known Member
I use T5 for vegging and they work fine for me.
I have a small grow box, and do not veg very long, so the high-output T5 does the job.

But there is something about 'canopy penetration' where HID excels.
I am unclear on the scientific reason why. All things being equal (e.g., lumens), HID is recommended for larger plants. It may have to do with the structure of an HID lamp and/or the reflector?

Here is a link that offers a recommendation (but not a lot of rationale):

http://www.4hydroponics.com/lighting/lightingHelp.asp
We've found that our T5 fixtures are great for
all vegetative growth.
With the "cool" spectrum bulbs, they're all you'll
need for small plants like leafy greens and herbs. For larger plants, T5's are
the best quality light to start your vegetative growth before switching to HID
lighting for fruiting/flowering. We recommend using T5's to get your plants up
to 8-12" in height before switching to HID's. For other plants like orchids or
bonsai trees, T5's are perfect. Use the "cool" bulbs (6500k) for vegetative
growth, and the "warm" (2700k) bulbs for flowering, or mix the two spectrums for
full-spectrum output. Find those types of grow lights here.


We recommend HID lighting for larger plants like
vegetables and other big flowering plants, and during the fruiting/flowering
stages of growth. HID lighting is superior to fluorescent lighting in that it
has the ability to "penetrate" the plants canopy, and cover a larger area. This
higher intensity light will get through the canopy and down to the lowest leaves
on your plants.
 

silverhazefiend

Well-Known Member
I don't really have anything relevant to say but i think ur math is off ..I don't kno if any t5 ho putting out 6,500 lumens per bulb ..I could be wrong tho ..

But the highest t5 Ive seen was about 5k for a 4 footer ..PLL lights produce 5 thousand lumens per bulb 2 footer ..
 

doniboy

Well-Known Member
I don't really have anything relevant to say but i think ur math is off ..I don't kno if any t5 ho putting out 6,500 lumens per bulb ..I could be wrong tho ..

But the highest t5 Ive seen was about 5k for a 4 footer ..PLL lights produce 5 thousand lumens per bulb 2 footer ..
Yes, you are correct, but even then it's more than a MH. I decided to go with a ballast anyway just so if 1 ballast or bulb ever dies on me in the middle of a grow, I always have a back up to use for flowering. Then I figure I can pick up CFL's for the veg room to hold me over.
 

prosperian

Well-Known Member
Pics worth a thousand words (5 week flower). MH is tight nodes and bushier plants. We are not growing stalks, we are growing bud locations during vegging. Some growers need to run T5 for reasons that make it a better solution. After using a 400w MH, I would never go backwards to T5.





 

doniboy

Well-Known Member
Pics worth a thousand words (5 week flower). MH is tight nodes and bushier plants. We are not growing stalks, we are growing bud locations during vegging. Some growers need to run T5 for reasons that make it a better solution. After using a 400w MH, I would never go backwards to T5.

Yea, the problem with that though is someone else will come along who claims the exact opposite of you, and then there will be others who say that MH bulbs aren't need at all. That they're a waste of energy, inefficient, and to use HPS for both veg and flowering. All these people will swear by their claims while supplying absolutely nothing to back them up with. Pictures of one side don't really help in a side by side situation though...

I'm going with hid's anyway for other reasons.
 

209 Cali closet grower

Well-Known Member
funny I always get more tighter nods with t5ho, as I run 400w mh and t5ho 8 bulb setup. For mother veg, I really like t5 setups, plus I can run 4 bulbs if I want, and have done in the past.


I say get the t5, if for mothers or clones. I



I want to know the why and how MHs are better than T5s? I'm a nub, but to me, they do not seem to be..


  • T5 fixtures last longer than a ballast.==No
  • T5 bulbs last longer than MH bulbs, AND cost A LOT less to replace.=No if you got a 8 bulb t5 setup
  • T5 spreads light more evenly than MH=yes but, just the top really
  • [FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]T5 are more efficient than MH setups.= No hid, will always be more efficient[/FONT]
  • [FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]T5 are simple, uncomplicated, have less components (no ballast, cool hood, ducting, etc), weigh less, and cost less in maintenance cost and replacement cost over in general.both will be the same cost to fix if it goes out[/FONT]
  • A Metal Halide Bulb 400W bulb produces about 29,000 Initial Lumens, but the amount of light these bulbs emit decreases big time with time. Basically after a few months of use, a 29,000 lum rated bulb isn't actually emitting 29,000 lumens anymore..., don't know where you got that, but , that's wrong
  • We all know the amount of light decreases rapidly within only a few inches of distance, so taking into account that T5 can be positioned closer to plants than MH and that the T5 doesn't need to be incased in some kind of glass air cooling fixture (which blocks even more light), I think that should even the lumen gap even more between the T5 and MH bulbs, no?Both need to be vented
  • [FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]A blue spectrum T5-HO bulb has 6,500 approximately. lums per bulb and it's my understanding that you can fix up to 8 tube in a 4" fixture within a 4x4 tent. If I go with a 6 tube fixture , that would be 39,000 lums correct? (6,500 * 6 = 39,000) Without the air cool hood glass and with being closer to the plant, wouldn't this be more light than using a 400 MH lamp?With a air cooled 400w you can putty much smash the plants in the glass, and you will not burn a plant. With my t5 I can't let the plants touch the bulbs, with out them getting burnt[/FONT]
 

doniboy

Well-Known Member
  • T5 fixtures last longer than a ballast.==No
  • T5 bulbs last longer than MH bulbs, AND cost A LOT less to replace.=No if you got a 8 bulb t5 setup (YES BECAUSE YOU ONLY HAVE TO REPLACE 1 BULB IF ONE GOES OUT INSTEAD OF ALL 8 OR HAVING TO SPEND $100+ ON A MH BULB. 400 watt metal halide lamp life = 18-20,000 hrs. but do not really last that long because they loose light fast. Fluorescent T5 lamp life = 35,000 hrs.)
  • T5 spreads light more evenly than MH=yes but, just the top really (which should be fine for under 2 ft vegging plants no?)
  • T5 are more efficient than MH setups.= No hid, will always be more efficient (HOW'S THAT? MH REQUIRE COOLING AND LOOSE INTENSITY FASTER WHILE STILL USING THE SAME AMOUNT OF ELECTRICITY.),
  • T5 are simple, uncomplicated, have less components (no ballast, cool hood, ducting, etc), weigh less, and cost less in maintenance cost and replacement cost over in general.both will be the same cost to fix if it goes out (http://tinyurl.com/chdlej7 and other source say other wise as far as cost go. I can link you to other source i have read. As far as actual cost to repair a broken one, I have no clue. All I know is the stated self life and warranties on most t5s are usually longer than ballasts.)
  • A Metal Halide Bulb 400W bulb produces about 29,000 Initial Lumens, but the amount of light these bulbs emit decreases big time with time. Basically after a few months of use, a 29,000 lum rated bulb isn't actually emitting 29,000 lumens anymore..., don't know where you got that, but , that's wrong
    (It's absolutely correct, mh bulbs loose intensity over time while still eating the same amount of electicity. This is why people say to change bulbs after a year even if the bulb still works. Google it.)
  • We all know the amount of light decreases rapidly within only a few inches of distance, so taking into account that T5 can be positioned closer to plants than MH and that the T5 doesn't need to be incased in some kind of glass air cooling fixture (which blocks even more light), I think that should even the lumen gap even more between the T5 and MH bulbs, no?Both need to be vented
  • A blue spectrum T5-HO bulb has 6,500 approximately. lums per bulb and it's my understanding that you can fix up to 8 tube in a 4" fixture within a 4x4 tent. If I go with a 6 tube fixture , that would be 39,000 lums correct? (6,500 * 6 = 39,000) Without the air cool hood glass and with being closer to the plant, wouldn't this be more light than using a 400 MH lamp?With a air cooled 400w you can putty much smash the plants in the glass, and you will not burn a plant. With my t5 I can't let the plants touch the bulbs, with out them getting burnt (I've read a lot of post and opinions on the matter, and this is the first I heard of this happening, but i'll take your word for it.)
You kind of lost me after you claimed that I was wrong about "the amount of light MH bulbs emit decreases big time with time." That is documented every where.
 

209 Cali closet grower

Well-Known Member
Look if a cap goes out on a hid mh ballast, it's about $15-40 to replace a cap. t50 ballast will be about $40-$70 to replace. My Mh ballast is going on 10yrs now
 

doniboy

Well-Known Member
I can show proof of burnt leafs from my t5 right now, if you want to see? Temp in room is 78f
I believe you. I'm not going with t5's anyway. I like the idea of having interchangeable backups. I can get another hid set with 1 of each bulb. If anything ever happens to my flowering bulb or ballast, I can steal the veg lights and put them in the flowering room, and then run to walmart or lowes for cheap cfls to hold me over in the veg room...
 

209 Cali closet grower

Well-Known Member
LOL smart ass. I said a 29,000 lum MH will no longer be a 29,000 lum bulb with in a few months which is true. The amount of light it emits starts to degrade faster than HPS and T5-HO. Do you do much comprehending?
So where you read this??? A 400w puts out 39,000 lums fyi, so how will it lose 29,000 lums in a few months???

I was just trying to help you? So how was I, a smart ass?
 

209 Cali closet grower

Well-Known Member
I believe you. I'm not going with t5's anyway. I like the idea of having interchangeable backups. I can get another hid set with 1 of each bulb. If anything ever happens to my flowering bulb or ballast, I can steal the veg lights and put them in the flowering room, and then run to walmart or lowes for cheap cfls to hold me over in the veg room...
All good.

good luck, I would take the hid too.
 

doniboy

Well-Known Member
So where you read this??? A 400w puts out 39,000 lums fyi, so how will it lose 29,000 lums in a few months???

I was just trying to help you? So how was I, a smart ass?
I looked up the lum output on one of the most used and respected bulbs that I seen most people mention they went with which was a 400w Hortilux MH. The output seems to vary with bulb manufacturers though....
 

prosperian

Well-Known Member
Yea, the problem with that though is someone else will come along who claims the exact opposite of you, and then there will be others who say that MH bulbs aren't need at all. I'm going with hid's anyway for other reasons.
Well, it is a forum. What you are asking for isn't going to come from on-line threads. I prefer books because in most cases the authors use controlled environments and document the variables precisely. Anyone doing that on here will go nuts fighting with all the rest of the members.

Each grow is unique to the individual grower even if you use identical equipment, strain, and grower experience.

RIU is for fun peppered with useful information here and there. Good luck on your grows!
 
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