T8s vs. 400 Watt MH conversion...The Shocking Results.(w/pics)

jawbrodt

jawbrodt

Well-Known Member
BiG PuFFer said:
so the one off ebay doesnt come with the best bulbs to use for vegging?
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No, because it's not sold as a growlight. The bulbs it comes with work great,(see pics) but if you want to change to 6,500K bulbs they are about $2 each, online. I have a bunch ordered, and they will be here in a day or two.
 
Sleepy79

Sleepy79

Member
I am running T8's as well, 3 fixtures (2 bulb) cheapest ones I could find. I am also running mix of 4 different brands of bulbs, 6500k 2800lu, 4100k 2800lu, 6500k 2700lu, 3000k 2950lu. I found that the seedlings were leaning towards the 4100k bulb more. Keeping the lights roughly 4" away from the tops and letting the plants grow to them will keep the node spacing tight. Keeping a 6" distance at all times will give them a controlled stretch.

Only reason why I went with the T8's over the HO T5's is the price. Two 2' fixtures would have cost me more than my three 4' T8's. I did find that an electrical supply store sells a HO T5 4' four bulb fixture at half the price of what a hydro shop asks. Something I will look into once these T8 bulbs start to degrade.
 
jawbrodt

jawbrodt

Well-Known Member
You should try running them at 1" or less, because that bumps the output to 5,000 lumens at the tops, and will give you that extra 3" of light penetration. I try to run mine as close as possible, which is usually 1/2' or less to the tallest plants. Also, those shoplights work okay, but have quite a bit less output if you check them with a light meter.(cheap ballasts)

Just trying to maximize. :wink:
 
KakKakKax

KakKakKax

Member
I'm running a T5 and have to literally keep it 20+ inches above well rooted month old clones, very impractical consider the amount of electricity wasted. I know I will be able to get it down to a couple of inches away from the tops in a few weeks but by then it would be better to re-pot the plants than keep them all crowded together.

I would agree with the T8, T12 approach, you get more than enough usable light for less $ and you don't have to worry about burning your plants. I found this out the hard way, set my ladies back almost 2 weeks trying to figure out the right height to hang at.
 

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AquafinaOrbit

AquafinaOrbit

Well-Known Member
Well of course t12 don't compare, a 2bulb fixture is 10dollars. For the price though they compare very well. Also was cooling ever mentioned? A HID 24" up or on with a cooltube and fan 10" up would give far different results.
 
Sleepy79

Sleepy79

Member
AquafinaOrbit said:
Well of course t12 don't compare, a 2bulb fixture is 10dollars. For the price though they compare very well.
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I think T12's put out a bit more lumens, but use a bit more watts. Bulbs are easier to find, more variety. Pretty much a toss up if going the T12, or T8 route.
 
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growone

Well-Known Member
i stumbled across this grow setup a ways back
just t8 bulbs, but mounted vertically
with results like these, who needs HID?

 
cowboylogic

cowboylogic

Well-Known Member
jawbrodt said:
For comparison reasons, I just took these pics of these clones that have been in soil for 11 days, vegging under this exact 6-bulb T8 light, http://cgi.ebay.com/T-BAY-6-LIGHT-T8-FLUORESCENT-FIXTURE_W0QQitemZ300388228440QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45f0889d58 with 5000K bulbs(natural sun spectrum). The first two pics are of the same three strains, also 11 days old. Notice the difference in growth, and how compact the plants are that are vegging under the T8s. The other plants were vegging under a 400 watt MH conversion bulb, set at 16-18"(average), and were stretching like crazy. I didn't realize how bad they were stretching until i made the switch, and was shocked by the results. :shock:

So, there's clear proof that T8s are an excellent choice for vegging, as long as you don't plan to veg some really tall plants. Anything under 20", is perfect for this setup.

Also, that T8 unit is only 200 watts, and clearly beat the 400 watt MH. Just imagine what two of them can do, at 400 watts. :cool: You can stick with T5's if you wish, but I'll be perfectly happy with the T8's, and not have to worry about burning the tops of the plants, while using less electricity for more coverage area. They also run alot cooler too, for those that have a concern with heat issues.

It is important to note that you can't use any old T8 light. This unit has just the right reflector and bulb spacing, along with 'high output' ballasts, which make all the difference. I tried the others, and they just can't provide this nicy bushy growth. Oh yeah...I had them under the MH for the first 2 days, which stretched them a little, or else they would look even nicer.

I don't know about you, but I'm convinced. I have 6,500K bulbs coming in a day or two,(and another T8 unit) and I can't wait to get those going. :cool:
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I agree t-8 and t-12 work great for vegging. I disagree with your statement about exact bulb spacing ect... The 2 bulb 4 foot fixtures you get for 10 bucks work just about as well. I use a homemade t-8, 6 bulbs in a standard 2'x4' fixture. Getting the same results as you. Oh ya, I turbocharged mine. I run only 2 bulbs per 4 bulb ballast. But like I said, the 10 buck cheapos work just about as well.
 
jawbrodt

jawbrodt

Well-Known Member
^I was thinking about 'overdriving' my light too, just to see the difference. Then i decided against it because it would use twice the electricity, defeating the purpose. You're setup sounds like it works really good. I wasn't really saying that this is the only T8 setup that will give these results, I was more saying that it's a good option because it's guaranteed to give excellent results, and is really easy to use. A good option for those who want to eliminate the guesswork.

What I meant by "exact bulb spacing" was that I saw other 6-bulb units with weird spacing, having 3 bulbs close together on one side, a large gap in the middle, then the other 3 bulbs on the other side of the fixture. Those wouldn't be good for growing, and should be avoided. I would say that the T8 shoplights give about 80% of the performance of this fixture, and the T12s give about 70%. They are a tad below the necessary minimum for vigorous growth, but will work pretty well if a sufficient number of fixtures are used. I wasn't quite satisfied, which is why I upgraded.

I noticed that T8 setup in the avatar above, and found it very interesting. Very tempting to give it a try, and get the extra yield from those lower branches. Of course, I would have to veg some nice sized plants to take advantage of their heigth, but I guess 4' isn't that tall, after the bloom stretch(they look bigger than that in the pic, but then i realized that the lights ar only 4' long) Hmm.....
 
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growone

Well-Known Member
Vincent.Gallo said:
did u have 2 traine this plant; look scary, can u grow it shorter and fuller?
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sadly, this is not my setup, from another grower's log
i was, to say the least, impressed with the results
i grow micro, my state has a ways to go before i grow the big plants
the efficiency of shorter tubes goes down, but i'd think some short t5's would produce good results
i really want this setup when NY goes MMJ, and i can qualify, could be a while
 
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