T8 vs T5 HO vs (maybe) LED?

Greatgardens · February 20, 2018

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 · February 20, 2018

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 · February 20, 2018

Quote:

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 · February 20, 2018

Quote:

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 · February 20, 2018

Quote:

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 · February 20, 2018

Quote:

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.

Worth1 · February 21, 2018

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 · March 14, 2018

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

Greatgardens · March 14, 2018

Quote:

Originally Posted by 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?

This one?

https://www.walmart.com/ip/Lights-of...light/46808020

They have a zillion on their web site. This one looks very nice -- pull chain and everything!

-GG

GoDawgs · March 14, 2018

After reading some discussions online about T12's vs T8's and others, I decided to replace four of my six very old T12 florescents with T8's. It was a good time to do that as the tubes needed replacing anyway.

Then I read that some folks use two kinds of tubes in one fixture to cover a wide light spectrum so I did that too. Each fixture has a daylight bulb (6500k) and a warm white tube (3000k). Both are 32 watts.

I do believe that the seedlings are doing better but I have noticed I need to check moisture levels a lot more often as the T8's are warmer than the old cool whites I was using.

I also have detected a very very slight leaning of seedlings towards the daylight tube so the trays just get turned around. All in all I'm satisfied. Got everything at Lowes as Home Depot didn't have near the selection. Two fixtures and four tubes plus tax for the first came to $58.67 for the first two sets so I decided a few days later to just go ahead and get two more sets.

FourOaks · March 14, 2018

GoDawgs... you will be satisfied with the T8s. They are a leap forward from the T12s, thats for sure. Just watch out for leaf burn. I didnt think it was possible, but believe me, it is.

Im at that point where an upgrade is somewhat inevitable. T5s vs LED. Or even possibly HID lighting.

I need some supplemental lighting in the seedling house. Im looking for something to hang from the purlins. Whether its HID, T5, LED...

Tiny Tim · March 15, 2018

FourOaks. I have and run LED's and HPS. HPS runs HOT. Nothing like a LED or Fluorescent fixture. I need to run my exhaust fan constantly. They do penetrate a bit deeper into your canopy. Spread or coverage is about the same with my MarsII 400 watt, 190 actual watt LED and my magnetic ballast 250 watt HPS.

Tiny Tim · March 14, 2018

Greatgardens, that is the light I have. It's very well made. Extruded aluminum body, ends are plastic. Mine's on a timer. But, the pull chain works smoothly.

Al@NC · March 14, 2018

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 · March 14, 2018

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.

February 20, 2018	#1
Greatgardens Tomatovillian™ Join Date: Feb 2010 Location: Indiana Posts: 1,124	T8 vs T5 HO vs (maybe) LED? 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

February 20, 2018	#2
FourOaks Tomatovillian™ Join Date: Mar 2016 Location: NC Posts: 511	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.

February 21, 2018	#7
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	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

March 14, 2018	#10
GoDawgs Tomatovillian™ Join Date: Feb 2018 Location: Augusta area, Georgia, 8a/7b Posts: 1,685	After reading some discussions online about T12's vs T8's and others, I decided to replace four of my six very old T12 florescents with T8's. It was a good time to do that as the tubes needed replacing anyway. Then I read that some folks use two kinds of tubes in one fixture to cover a wide light spectrum so I did that too. Each fixture has a daylight bulb (6500k) and a warm white tube (3000k). Both are 32 watts. I do believe that the seedlings are doing better but I have noticed I need to check moisture levels a lot more often as the T8's are warmer than the old cool whites I was using. I also have detected a very very slight leaning of seedlings towards the daylight tube so the trays just get turned around. All in all I'm satisfied. Got everything at Lowes as Home Depot didn't have near the selection. Two fixtures and four tubes plus tax for the first came to $58.67 for the first two sets so I decided a few days later to just go ahead and get two more sets.

March 15, 2018	#12
Tiny Tim Tomatovillian™ Join Date: Feb 2018 Location: Near Albany,NY Posts: 90	FourOaks. I have and run LED's and HPS. HPS runs HOT. Nothing like a LED or Fluorescent fixture. I need to run my exhaust fan constantly. They do penetrate a bit deeper into your canopy. Spread or coverage is about the same with my MarsII 400 watt, 190 actual watt LED and my magnetic ballast 250 watt HPS.

March 14, 2018	#14
Al@NC Tomatovillian™ Join Date: Jun 2012 Location: Vernon, BC Posts: 720	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

March 14, 2018	#15
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	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.