T8 vs T5 HO vs (maybe) LED?

[Greatgardens]

I'm considering replacing the last of my aged T-12 fixtures, but I'm really on the fence between T8 and T5 HO. From everything I've been able to read and see on Youtube, LED isn't really a very good option for "consumer" grow lights at this point (at least for vegetative growth). Similarly, I don't want the expense of the HPS lights. So this is primarily about T8 and T5 HO.

Although T5 HO is slightly more efficient than most T8 bulbs, some of the newer T8's are just 28 watts and would appear to be equally efficient. Further, when the purchase costs are considered, the scale appears to tip to T8.

Do we have any strong proponents of T5's? Or perhaps LED's? Curious to hear others thoughts on this.

-GG

[FourOaks]

This is something I have been considering myself. The difference is that I am already invested into T8s.

I saw a T5 system that my local Hydro store has setup, with seedlings under the lights. So that sparked a conversation with them. And I will say, the seedlings looked GREAT! But, and there is always a but isnt there? They had the lights about 2 feet from the top of the plants. I asked if that was normal, cause that wont work for me.

Heres a couple reasons why I havent personally jumped on the T5s.

1. Cost. If I was starting completely from scratch, it would be a better option. As it is right now would require an infrastructure change, along with purchasing the lights, that my "business" simply cant absorb.

2. Infrastructure. I currently use metal shelving, with lights on every shelf. The T5s need more room.

3. T8 does offer an HO option. This is worth exploring some more.

It really depends whether or not you can make them work for your situation. I love the results they got, but I would have to figure out a whole new arrangement. Not to mention, I pretty much move seedlings out to the seedling house as soon as they germ. So, the benefits dont out weigh the cost. Not yet anyways.

[rhines81]

Originally Posted by FourOaks

They had the lights about 2 feet from the top of the plants. I asked if that was normal, cause that wont work for me.

Not sure why.... my T5s are 1-2" above my plants, not feet? That seems odd unless they want leggy plants. I never get any burning or excess heat residual... everything is just fine.

[FourOaks]

Originally Posted by rhines81

Not sure why.... my T5s are 1-2" above my plants, not feet? That seems odd unless they want leggy plants. I never get any burning or excess heat residual... everything is just fine.

Oh believe me, they were not leggy. The ballast had 8 bulbs in it. Ill see if I can find the unit they had on display.

[rhines81]

Originally Posted by FourOaks

Oh believe me, they were not leggy. The ballast had 8 bulbs in it. Ill see if I can find the unit they had on display.

pffft, 8 bulbs?? sounds like it would be extreme overkill for my situation... I have 2 bulbs per fixture and grow on shelves, so excess vertical space would definitely be a no-go!

[FourOaks]

Originally Posted by rhines81

pffft, 8 bulbs?? sounds like it would be extreme overkill for my situation... I have 2 bulbs per fixture and grow on shelves, so excess vertical space would definitely be a no-go!

Here ya go:

https://www.amazon.com/Sun-Blaze-Flu.../dp/B000AXTNCS

Unit delivers about 40000 lumens. This is the EXACT system they had on display.

[bower]

The price of integrated LED fixtures has certainly come down. Many choices on amazon:
https://www.amazon.com/22w-4ft-Integ.../dp/B00KVHO51C

There are lots of great deals at 4000 and 5000 K, not as many but at least a few offerings in 6500 K. Most of them have a 5 year warranty. Some are certified, some not (personally I think it's a better investment to get something that meets a code of standards, somewhere).

Why I would choose integrated LED?
- they really pump out the lumens, and a fraction of the power cost
- they would last me a good 25 years for seed starting, no bulbs to replace etc
- there's no hazardous waste, as there is with fluorescents
- when you consider bulbs + fixtures, the integrated LED is very close in price to the fluorescent, and if you consider replacing the bulbs every 5 years, the fluorescent is long term more expensive

[Tiny Tim]

Four Oaks, that really seems to be a lot of lumens for a T5 fixture. Are they really more efficient than a HPS or an LED of which I run both in my tents. I can believe the distance though,solely based on the heat they'd produce. The Lumens to watt calculator I used shows 27.000 for that fixture. Still a lot. A little more than my 250 HPS. I also run A Mars 300 watt LED and a MarII 400 watt LED. But, they use PAR value not Lumens. Good luck with that fixture and as always Happy gardening.
Tim

[FourOaks]

Originally Posted by Tiny Tim

Four Oaks, that really seems to be a lot of lumens for a T5 fixture. Are they really more efficient than a HPS or an LED of which I run both in my tents. I can believe the distance though,solely based on the heat they'd produce. The Lumens to watt calculator I used shows 27.000 for that fixture. Still a lot. A little more than my 250 HPS. I also run A Mars 300 watt LED and a MarII 400 watt LED. But, they use PAR value not Lumens. Good luck with that fixture and as always Happy gardening.
Tim

I wont disagree with you. Based off of info. from 1000bulbs.com, that is 2 times as powerful as the 32 watt T8s that I am currently using.

There are now HO T8s. Upwards of 50 Watt. But, the bulbs are NOT cheap.

[Tiny Tim]

I can only comment based upon my personal experience. I have run cool white 4"tubes. I also ran an 8-23 watt CFL fixture I made,184 watt total.

When I switched to the small Mars 300 it was a day and night difference in growth.
Another benefit, it doesn't put out the heat my 8-23 watt CFL light did.
The Mars 300 only draws 130 watts.
The Mars 300 is a full spectrum fixture.
The Mars II 400 watt is switchable for Vegetative growth only or Flower only or both. The actual watts depend on switch position,with a max of 190 watts.

It preforms much better than the 250 watt HTG magnetic ballast HPS.

The HPS requires extra cooling the LED does not.

I'm in no way endorsing this brand of light. I'm only explaining my personal experiences with these fixtures.
I do know some folks burn out diodes on the cheaper LED's like mine, almost always because the have them in enclosed tent with no air exchange. Hope this helps..Happy gardening folks..

[FourOaks]

I took a gander at the Mars lights. Interesting. I see there is also a 600 watt unit.

I guess it all depends on your ultimate goals.

I still like using the T8s as a ready made heat mat! I just stack my flats ON TOP of the T8s and utilize the fact that they emit a healthy dose of warmth.

Cover the shelving unit with plastic, and voila', instant germination chamber. I measured the soil temp right at 82 degrees!

[Worth1]

I was sitting on top of a shelf wiring up a panel yesterday among a vast amount of lamps to grow plants.
But alas they weren't mine to take.

Worth

[Tiny Tim]

Just bought one of these from Wally's. Never used this style LED before. If anyone has, how far from tops of seedlings?

[Al@NC]

I just bought a smaller LED light off of Amazon and the manufacturer recommends 10"-24" from top of the plants as well. They don't explain why though... I'm assuming because of the wavelengths or something?









Al

[bower]

4500 lumens is a lot compared to the typical fluorescent, iirc my 6500 k comes in at 3750 lumens for the pair. The LED lights I bought this year are 4000 lumens. I did have some ?? scorchy leaves ?? on certain brassicas under the LED but don't know for sure if that was the cause.

If it was me, I think I'd set up at least 8 inches to a foot above the seedlings, and wait to see the effects. If they're stretching to get closer, bring it down. But I'm only guessing.