T5HO entire grow vs HPS

doniboy

Well-Known Member
Anyone grew autos using only T5s and grew using a combo of t5s veg and hps flowering that can compare the two? I just got some t5 3,000k spectrum bloom bulbs, and was thinking about whether lighting I should use.
 

dl290485

Well-Known Member
If you are going to use T5 just keep the bulb as close as you can (within reason, don't get too hot etc)
Keep the plant height to an absolute minimum and ideally make the growth occur horizontally. I say this because the fluro's start with a not very impressive light intensity and it drops off pretty rapidly with distance. BUT- it does have enough energy and there are plenty of people on this site who can show pictures to prove it. It's all about shaping the grow so the light is being used efficiently and all the bud sites are as close to the lamp as possible. Even with a HPS, if you grow a 2 meter tall upright trunk, more than half of the plant won't get enough light with only really the very tip doing well and the rest will go to waste- so you always have to manage your canopy what ever you use..... but just as a disclaimer, i'm not a T5 grower i'm just talking from a logical point of view and also based on seeing some great photo's of other people's grow.

As for comparison- that would be tricky to do because if you compared my 2m tall under HPS example with a even canopy scrog with bud site close to the T5 then you could say "HPS sucks, my yield was tiny. It has nothing on my T5" when the difference wasn't really the light but how each of them were used.
 

doniboy

Well-Known Member
Anyone grow autos under the same conditions using t5s vs hps that can share their experience?
 

doniboy

Well-Known Member
Looks like it's up to you :mrgreen:
Yea, thanks for helping. I pretty much already understand the concepts behind the use of T5s, but was wondering how people were doing when growing the regular way using t5's vs hps. I do not have a setup to scrog or anything fancy.
 

justugh

Well-Known Member
t5's rock do to the low heat

given lumens are engery for the plant to equal a hps 400 that is 2 t5s 4ft 8 bulb that is 40000 lumens per unit ....4ft are 5000...2ft is 2000 lumens per bulb this is standard base for HO t5
hps 400 55000 lumens
so in theroy the hps should be taller and thicker do to the amount of engery

but it comes down to heat reduction hps u need a strong fan tubing and possible ac
where t5 a strong fan is about all u need if u want negitive pressure in a controll evo ......t5 will raise 10 to 15 of what ever the out side air is (so far in my set up )
 

dl290485

Well-Known Member
I've never seen a side by side comparison for t5 vs hps. I'm guessing everyone is too wrapped up in what they are doing or just don't have the room or money for the experiment.

But as using a 'regular way' to grow with T5 compared to HPS- to me that sounds like using the T5 wrong. As I said previously, the starting light intensity is rather low comparitively and the drop off is very nasty. Roughly 1ft from the lamp reduces the intensity by about half. To go another 1ft (so 2ft from the lamp) the intensity drops again by roughly 50% (leaving you with only 25% of the lamp intensity). Now with a 600w hps, 2ft from the lamp is actually the recommended safe hanging distance... so ya it's a bit hard to compare both types of lights if you try to grow exactly the same way. You have to use them to their own strengths and avoid their weaknesses.
If you didn't want to scrog, you could do a SOG where you 12-12 from seed or 12-12 from rooted cutting and the plant will only grow about 2ft tall each (and you just put lots next to each other to fill the space). That's actually a good technique for either lamp (as is scrog of course).
But yeah if you want to compare growing a 1.2 meter tall plant under a HPS to T5.. that's just not fair on the T5 because that isn't playing to it's strengths (low temperature being one of them).
 

doniboy

Well-Known Member
Y
I've never seen a side by side comparison for t5 vs hps. I'm guessing everyone is too wrapped up in what they are doing or just don't have the room or money for the experiment.

But as using a 'regular way' to grow with T5 compared to HPS- to me that sounds like using the T5 wrong. As I said previously, the starting light intensity is rather low comparitively and the drop off is very nasty. Roughly 1ft from the lamp reduces the intensity by about half. To go another 1ft (so 2ft from the lamp) the intensity drops again by roughly 50% (leaving you with only 25% of the lamp intensity). Now with a 600w hps, 2ft from the lamp is actually the recommended safe hanging distance... so ya it's a bit hard to compare both types of lights if you try to grow exactly the same way. You have to use them to their own strengths and avoid their weaknesses.
If you didn't want to scrog, you could do a SOG where you 12-12 from seed or 12-12 from rooted cutting and the plant will only grow about 2ft tall each (and you just put lots next to each other to fill the space). That's actually a good technique for either lamp (as is scrog of course).
But yeah if you want to compare growing a 1.2 meter tall plant under a HPS to T5.. that's just not fair on the T5 because that isn't playing to it's strengths (low temperature being one of them).
So how can using the sog method on a 2' flowering plant with either light be okay, but not okay when flowering a 2' auto?

Ya'll ever hear about anyone lollipopping an auto before?
 

dl290485

Well-Known Member
Sorry I forgot I was in the auto thread.
Yes i get you now, normal for auto...

Well some auto's are shorter than others... I guess that would be the only difference when picking a strain more ideal for T5 (if you are doing SOG not training it)
 

growingforfun

Well-Known Member
The only time I grew autos I used a 8 bulb t5ho 4ft fixture, I got buds that were a letdown. In my other tent I had a 1000 watt hps an got huge colas like a ft long and super sticky, those were photoperiod plants tho. The autos nugs were like fingernails
 

doniboy

Well-Known Member
Well i decided to scrog with my autos and going ti keep my t5 like 2 inches above the whole grow. Hopefully that'll give me somewhat similar results to a 400w HPS.
 
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