16 T5 fluorescent bulbs vs 1 600 watt MH bulb for vegging up to 4-9 weeks

[Stonefree69]

T5s vs MH in late veg

For vegging 4-9 weeks (clone or seed) in veg station up to 12 sq ft lit area (17” x 51”) for 6 plant sites (17” square) I currently have 16-54 watt T5s and want to compare them to 1-600 watt HID MH.

I had an 8 bulb T5 fixture 1st and added 2-4 4 bulb fixtures for early veg over 2 rows of 3 8.5” net bottom pots (that start off with just 216-432 watts total) and that's how I ended with current veg lights. I also have 2-600 watt HIDs for flower room (expanding that to 4X600 or 2,400 watts). So I want to possibly "upgrade" my current 16-54 watt T5s (832 watts, 80,000 lumens) and compare to: 1-600 watt HID MH (645 watts, 75,000 lumens & w/10% boost 670 watts, 82,500 lumens).

I'm comparing these ballasts & fixtures, which are near the top of the line for utilizing respective technologies:

Fluorogrow Evergreen 4 & 8 bulb T5 fixtures w/Racehorse ballasts & Plantmax 6,500K T5 bulbs
Gavita Digistar 600 watt ballast with Digilux 600 watt or similar good brand digital capable MH bulb (also using 10% boost) w/Blockbuster 6” light hood or similar efficient model like the Radiant.

So a quick comparison of T5 bulbs with the MH bulb:

16 T5 fluorescent bulbs: 80,000 lumens, 864 watts: 92.6 lumens/watt efficiency
1-600 watt MH bulb: 75,000-82,500 lumens (w/ 10% power boost), 645-670 watts: 116.3-123.1 lumens/watt efficiency

For one it looks like the 600 watt should easily win with efficiency (116.3/123.1 vs 92.6 lumens/watt or up to 32.9% more efficient). What the T5s have going for them is even coverage for young vegging plants that are less than 1-2 feet high. Even at 8 weeks from seed and plants are still 2 feet or less (depending on grow method), the T5s still are competing as far as light coverage is concerned, but somewhat less efficiently.

What would you do - go for the even coverage provided by the T5s to the young plants in veg (@ 1-2 feet max height) or go with the 600 watt MH bulb & Blockbuster light hood? This also would be to cover a 17” by 51” area or 12 sq ft. That also does come out to 50 watts/sq ft fot the 600 way MH bulb. 6 young but decent sized vegging plants (up to 1-2 feet tall) fit perfectly for this too (17 inches square).

I like to call one area my veg station as it's only 3' by 5.5' total area (sectioned off in my bedroom by 4' x 8' foamboard panels) and my other area the flower room, not “station” as it's about 9' by 15' including a nice 2' by 5' closet with 3 strong storage shelves.



Again to sum it up: I'm saving going with the 600 watt MH (240 volts) about 200 watts power and that's running 18 hours in veg (at least). But good even light coverage is also a big priority for young plants. I know T5s have the great light coverage needed but feel if I measure light output @ canopy perimeter w/a lumen or PAR meter the MH will still be close there in output. So if I measure the light coverage at least on par or better than the T5s MH wins all the way. Just T5s for that early veg when I need just 20-40,000 total lumens.

Heck with 200 watts saved I could run a 1/4 hp chiller instead or insulate and still run less total power w/a 1/10th hp chiller (veg setup using less water & cooling demand too).

But if anyone has found the T5s to beat out a 600 watt MH in late veg please let me know. Not early veg, for me I know the answer running 4-8 T5s (also a 400 watt MH is about same efficiency as the T5 bulbs, it's the 600 & 1,000 watt HIDs that run more efficient).


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[OvergrowDaWorld]

I vegged for years and years under a 600w MH w/ aircooled hoods.
Ive recently switched over to an 8 bulb T-5 and a 4 bulb T-5 to veg all my plants for 8 -10 weeks, that will be put under 2 -600w hps lamps. I top the hell out of my plants so I get multiple heads. This way its a full canopy and they get even distribution of the light.
Once they get above 18" I would advice switching to 600w MH's to penetrate any lower stuff. The T-5's are inefficient at this point as the lower stuff will yellow and fall off.
Using 2 - 8 bulb T-5's would be the best, most effecient way of growing tight, thick bushes, with very close internodes and establishing a fantastic plant in 8 weeks. If I need more veg time, Ill veg for a week or 2 (if needed) in my flower room under 2- 600w MH's, then switch to HPS when I flip em'.

My 600w MH would grow the plants too tall and the internodes further apart than the T-5's, when younger. Much better structure and growth is my experience. I freakin love my T-5's.

 

[one.sixoneeight]

the t5 will kill the 600 mh

 

[Stonefree69]

I vegged for years and years under a 600w MH w/ aircooled hoods.
Ive recently switched over to an 8 bulb T-5 and a 4 bulb T-5 to veg all my plants that will be put under 2 -600w hps lamps.
Using 2 - 8 bulb T-5's would be the best, most effecient way of growing tight, thick bushes, with very close internodes and establishing a fantastic plant to flip when its ready.

My 600w MH would grow the plants too tall and the internodes further apart than the T-5's. Much better structure and growth is my experience. I freakin love my T-5's.

the t5 will kill the 600 mh

Wow you 2 are making sense. I haven't got the MH yet like I said have 16 T5s, so guess I'm good where I'm at?! Yes I've observed "unbeatable" early growth as well. What had me considering was saving 200 watts. Light is spread more even thru canopy using T5s with similar light output and the plants being short (up to 1-2' max) at this stage can take full advantage of it.

 

[fatigues]

T5s, multi PL-Ls light fixtures (a 55w PLL is essentially a 48" T5HO bent back on itself to form a 22" long lamp with a U-bend ) and even a PL-L /LED combo unit has the advantage of delivering a lot of light more evenly over a given space than a MH will, and at a range much closer to the plants without significant heat issues.

I'm not sure that it is going to have the penetration to move your plants along for a VERY long veg time as the initial post suggests, though. 6-8 week veg and plants "1-2 feet high" seems to introduce a disconnect between time and height. Those two figures together in the same sentence don't work all that well for me. A lot of this can come down to semantics as when the "veg" period starts and the "seedling/clone" period ends. So that probably explains it

A suggestion that 18" tall would be the max for a T5 fixture to usefully penetrate seems a reasonable limit on expectations.

 

[Mister_D]

Going to toss another wrench in your gears. Over the last year or two I've been experimenting with many different grow related situations, lighting being one of them. As this relates to what you have going, I've been testing veg lighting, and the effects of having overlapping light. What I have found is: t5's and t8's do a much better job of keeping an even canopy than hps or MH (point source vs linear light sources). Also as others have noticed, nodes tend to stack tighter under flouro lighting. Now the real upset, for me at least, was when I tested t5 vs t8. The t5's produce twice as much light (measured with a light meter), and used twice the wattage of the t8's, but growth was almost exactly the same between the two bulbs. I'm talking maybe two more inches of growth in a 3 week period, and "slightly" better node spacing with the t5's. Not a significant enough gain for me to justify using double the wattage. Needless to say I now veg all my plants under 10 dollar t8 shop lights with Philips cool white bulbs (the best I've found for plants) from Wal-Mart. These plants generally reach ~18" tall before flower, zero problems with penetration. I use 12 shop lights to evenly cover every inch of a 4x8' veg table. Uses less watts than two 8 bulb t5's, with better coverage, and less heat to deal with. Plus if you some reason forget to raise the lights, and a plant decides to grow into the bulb, chances are it's not going to burn the leaves like a t5 would. To summarize, t8's are cheaper to buy and run, allow more flexibility in canopy depth (lower some lights for the smaller plants while raising others for larger ones), create waaaaaaay less heat than t5's, lowering cooling costs and equipment. Not to mention the savings in lighting wattage. Seriously I have four 8 bulb t5's just collecting dust because I refuse to use them any more.

 

[Stonefree69]

T5s, multi PL-Ls light fixtures (a 55w PLL is essentially a 48" T5HO bent back on itself to form a 22" long lamp with a U-bend ) and even a PL-L /LED combo unit has the advantage of delivering a lot of light more evenly over a given space than a MH will, and at a range much closer to the plants without significant heat issues.

I'm not sure that it is going to have the penetration to move your plants along for a VERY long veg time as the initial post suggests, though. 6-8 week veg and plants "1-2 feet high" seems to introduce a disconnect between time and height. Those two figures together in the same sentence don't work all that well for me. A lot of this can come down to semantics as when the "veg" period starts and the "seedling/clone" period ends. So that probably explains it

A suggestion that 18" tall would be the max for a T5 fixture to usefully penetrate seems a reasonable limit on expectations.

I see what you mean. 8 weeks from clone and T5s are not going to cut it as they'll likely be well over 2 feet. I was generally meaning 1-2 feet from 4-8 weeks veg from seed not clone. But if using clones I guess it would mean 4 weeks veg not 8.

Yes 18" is about what you want to do max from T5 or PL-L bulbs with a decent fixture. As I noted 1-2' maybe 2' is stretching a bit but I have the Fluorogrow Evergreen 8 bulb T5 and it had a tight footprint for T5s: 16" by 36". Your usual 8 bulb T5 fixture is about 20-22" or so wide. That's why I said up to 2 feet penetration but still stretching it maybe. Here's the measurement for Fluorogrow Evergreen 8 bulb T5 fixture (693 fc average which is pretty bright at 18", with inverse square law @ 24" should be close to 390 fc or about 56% intensity, 36" (double 18" distance) would be 1/4th light intensity etc.):

 

[fatigues]

Needless to say I now veg all my plants under 10 dollar t8 shop lights with Philips cool white bulbs (the best I've found for plants) from Wal-Mart. These plants generally reach ~18" tall before flower, zero problems with penetration. I use 12 shop lights to evenly cover every inch of a 4x8' veg table. Uses less watts than two 8 bulb t5's, with better coverage, and less heat to deal with. Plus if you some reason forget to raise the lights, and a plant decides to grow into the bulb, chances are it's not going to burn the leaves like a t5 would.

While I'm not old enough to have actually tried to do this, there are those here who well remember using those shop lights and backed the top of each lamp lamp with aluminum tape to provide some extra light restriking and then scrogged and wove their plants through chicken wire to FLOWER with those same shop lights before HIDs became the standard.

T8 shop light fixtures have a long and venerable history when it comes to indoor growing.

 

[Mister_D]

While I'm not old enough to have actually tried to do this, there are those here who well remember using those shop lights and backed the top of each lamp lamp with aluminum tape to provide some extra light restriking and then scrogged and wove their plants through chicken wire to FLOWER with those same shop lights before HIDs became the standard.

T8 shop light fixtures have a long and venerable history when it comes to indoor growing.

Guess that shows my age

 

[Stonefree69]

Going to toss another wrench in your gears. Over the last year or two I've been experimenting with many different grow related situations, lighting being one of them. As this relates to what you have going, I've been testing veg lighting, and the effects of having overlapping light. What I have found is: t5's and t8's do a much better job of keeping an even canopy than hps or MH (point source vs linear light sources). Also as others have noticed, nodes tend to stack tighter under flouro lighting. Now the real upset, for me at least, was when I tested t5 vs t8. The t5's produce twice as much light (measured with a light meter), and used twice the wattage of the t8's, but growth was almost exactly the same between the two bulbs. I'm talking maybe two more inches of growth in a 3 week period, and "slightly" better node spacing with the t5's. Not a significant enough gain for me to justify using double the wattage. Needless to say I now veg all my plants under 10 dollar t8 shop lights with Philips cool white bulbs (the best I've found for plants) from Wal-Mart. These plants generally reach ~18" tall before flower, zero problems with penetration. I use 12 shop lights to evenly cover every inch of a 4x8' veg table. Uses less watts than two 8 bulb t5's, with better coverage, and less heat to deal with. Plus if you some reason forget to raise the lights, and a plant decides to grow into the bulb, chances are it's not going to burn the leaves like a t5 would. To summarize, t8's are cheaper to buy and run, allow more flexibility in canopy depth (lower some lights for the smaller plants while raising others for larger ones), create waaaaaaay less heat than t5's, lowering cooling costs and equipment. Not to mention the savings in lighting wattage. Seriously I have four 8 bulb t5's just collecting dust because I refuse to use them any more.

Thanks Mister_D. Yeah those 8 bulb T5s can give off some heat. But I now have a 192 sq ft enclosed veg area (8'x8'x3') I vent with an 8" fan. On half speed 375 cfm I'm still getting Heath Robinson like air exchange @ 2 times per minute. Otherwise temps climb to mid high 80's fast for me.

Day 64 from seed (3/23/2013), it was for s**ts & giggles, bro's bag seed the same day I made a donut and put in an HPS bare bulb for flowering. That's over 2 feet (buckets are 16" high) @ 8 weeks from seed and they started great but had a bit of a slow start weeks 2-4 then took off...

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Ended up hitting 8 foot ceiling as I had to delay flowering for a few weeks:

 

[wantaknow]

I have both also ,t5 are great but put off some heat !my two 600 are vertical with no hoods I could add two more if I had them there great ! as tony would say ,I had 1k but could not deal with the heat issues in my small area,t5s are awesome for kick starts and vegging in a tent and taking clones to run in the flower room 10 -4 over and out

 

[Phaeton]

Small, medium, and large.
I use the fluorescent tubes for specific spectrum from the side and CMH or LED to feed chlorophyll from above.