LED LIGHTS

[biscuitridge]

I use three COB chips to cover a 2'x 5' area ,I run them at 50 watts each,so 150 watts that size is cheaper than t-5s,I get about 40000 lux at top of plants,the nice part is that they are dimmable and white, not that nasty burple color.I can actually grow very nice lettuce organically quite a bit cheaper than buying it at the store.it's a win win situation.

[bower]

Some extra pots of Yu Choy Sum and others got stuck in windows due to lack of light space. Direct comparison of the Yu Choy under the LEDs, there's no question they're getting plenty of good out of it. They are much bigger, large leaved etc. while the ones in the window are spindly.
Also my cut and come again lettuce and arugula have done fine without being super close to the LED. I kept the light 6-8 inches above them to try and cover the wider area - no sign of any stress and they're as big as is typical at 30 days. So I'm pretty pleased with the 4000 lumens, even if it is just a 4100 K.

[Benign Majesty]

Originally Posted by biscuitridge

I use three COB chips to cover a 2'x 5' area ,I run them at 50 watts each,so 150 watts that size is cheaper than t-5s,I get about 40000 lux at top of plants,the nice part is that they are dimmable and white, not that nasty burple color.I can actually grow very nice lettuce organically quite a bit cheaper than buying it at the store.it's a win win situation.

May I ask what COBs you are using and where you bought them? It sounds a lot more practical than the $400 video light panels that I'm using.

[JosephineRose]

Forgive my idiocy, but has technology gotten to the point where we can replace fluorescent bulbs in existing grow light fixtures with an LED?

If they work well and don't give off heat and don't burn leaves that touch them, I'm sold. I have T5s and T8s I'd love to swap out rather than starting from scratch with new fixtures.

[Cole_Robbie]

I haven't tried the specific lights being discussed, but LEDs as a technology work great as grow lights. The issue for me is initial cost. There is a power savings with LED, but all of us pay different rates for our electricity, so the time it takes you to make back your money in energy savings is thus different for everyone. My power is fairly cheap, so that time would be the longest for me.

[oakley]

Originally Posted by JosephineRose

Forgive my idiocy, but has technology gotten to the point where we can replace fluorescent bulbs in existing grow light fixtures with an LED?

If they work well and don't give off heat and don't burn leaves that touch them, I'm sold. I have T5s and T8s I'd love to swap out rather than starting from scratch with new fixtures.

Yes, you can replace your old bulbs and replace with LED using the same
fixture. They come with a retrofit kit. Takes just some minor fussing.

I needed more fixtures last year so I purchased when I saw them at Costco. Still wanted my old
lights to compare how the plants did under both. The LED's are great.

[biscuitridge]

Cree cxb3590 -3000k and 3500k. ,they are bright enough to grow tomatoes all the way to maturity, I have a 3+lber ready to harvest soon,they get about 35000 to 40000 lux at top of plant .
The savings aren't in just the electricity costs but also in bulb replacement costs,plus you'd have a very difficult time trying to grow a indeterminate beefsteak with t-5s or the led retro fixture,just not enough light to penetrate the canopy.

[bower]

Originally Posted by JosephineRose

Forgive my idiocy, but has technology gotten to the point where we can replace fluorescent bulbs in existing grow light fixtures with an LED?

If they work well and don't give off heat and don't burn leaves that touch them, I'm sold. I have T5s and T8s I'd love to swap out rather than starting from scratch with new fixtures.

A friend of mine recently bought a sixpack of LED T8 replacements - plug and play variety. They didn't work, and possibly this technology is not quite mature, and/or you have to be careful what brand you buy because there may be great deals on less than great merch. The price on these seems to be about 2X the price of fluorescent bulbs, but (in theory at least) they should last 3-4 X longer iirc. The other thing I read in reviews, is that they may not realize the full power savings that are billed, depending on the ballast type in the old fixture.
The other type of 'retrofit' LED - not compatible with the old ballasts - requires you disconnect the ballast and then reconnect the wires to the LED bulbs. This type bulb is possibly the least expensive (or very close to the price of fluorescents) but requires some electrical work. The electronics that make the LED work are inside the light tube, so you do lose a bit of light length. Maybe not a problem if there's a high lumen output.

[TexasTomat0]

I'm using homemade COB lights, CBA 3070's. They work great and you can mix in different K colors as you need them.

[PhilaGardener]

Originally Posted by bower

A friend of mine recently bought a sixpack of LED T8 replacements - plug and play variety. They didn't work, and possibly this technology is not quite mature, and/or you have to be careful what brand you buy because there may be great deals on less than great merch.

The plug and play LEDs only work with fairly new electronic ballasts. I tried some in my older shop units and they didn't work in that application for that reason.

[dfollett]

Somehow I double posted......

[dfollett]

The T5HO direct replacement LED tubes say they don’t work with all ballasts. I don’t know how to check the ballast for compatibility other than to try some. Someone somewhere probably has a list. My fixtures were T5H0 and the tubes were 54-watt. I just took a chance – and they worked.

In my real life, I manage a data center and we’ve done some research into fluorescent vs LED lights for efficiency purposes. My facility has T8 lights, rather than T5s. They make an LED T8 replacement tube where the same tube works with or without the ballast. I have not been able to find something comparable in T5s. The T5 LED tubes are either with ballast or without, but not both.

I had my electrician measure the difference in power consumption with and without the ballast because of the extra cost involved in removing the ballast. Anyone can change a tube with the ballast left in place, but only the electricians can remove the ballast, rewire and change the tube for the no-ballast tubes. The T8 replacements that can go either way replace 32-watt fluorescent tubes - both 4100K . When replaced leaving the ballast in place, the LEDs used 15 watts. When the ballast was removed and the same LED tube used 10 watts (We actually replaced a bunch and averaged the energy use). There was not noticeable difference in brightness with or without the ballasts, but the LEDs were significantly brighter and whiter than the fluorescent lights, but they were several years old.

It makes sense to remove the ballast where it is practical to do so from a labor and access perspective. Those that work with the ballast make sense where removing the ballast is a pain. I still haven’t decided whether to remove the ballasts when I make the change on a large scale….

[biscuitridge]

Here's my tomato that was grown under my COB led lights.just picked today.3.06 lbs.

[Greatgardens]

Is 6000k preferable to 5000k? I was thinking that 5000k is the usual daylight rendering. I'm still using some older T12 plant fixtures that I really need to update.
GG

[bower]

Originally Posted by PhilaGardener

The plug and play LEDs only work with fairly new electronic ballasts. I tried some in my older shop units and they didn't work in that application for that reason.

Yeah I was looking at some possible replacements again last night - turns out the Phillips ones which HD has locally will only work with an "instant start ballast". Also another variant on the do/don't plug and play, these only work WITH a ballast.
Seems like most of the "with or without ballast" ones work better without (as well as not with all ballasts). As Dan was saying, the power dif will add up over time. Also I read that the LED tube may fail prematurely if the ballast fails. So it is better to remove the ballast and rewire. I'm not sure if an electrician is required absolutely for that... I'm sure there's a video on YouTube.