100w replacement LED bulbs for small spaces

I recently found some 100w replacement bulbs (14.5w), all I could find before were the 40w and 60w ones. I was using the 60s but they were still a little too weak for good growth of rooted clones. The 100s really made an improvement. The plants are much more vigorous. It was 3 of the bulbs in the chamber, so almost exactly 10w per sq ft. Seems to suffice, since the plants are all less than a foot tall at their largest. I find that 12 such clones with only the 3 weeks total rooting/veg will in fact fill out a full height 3'x1.5' are chamber, 3 containers with 4 clones each. More causes overcrowding and no advantage. Fewer will work but you wouldn't get much yield unless they were veged longer than I want to. The 3 weeks works perfectly with my 3 week rotation system.

I only veg my plants for 3 weeks, including rooting time, so I need to get as much growth as possible in that time, due to space limitations, only have a small cabinet for the purpose, 3'x1.5'x 1.5' high. I leave the diffusers on, makes it less harsh on the plants and spread it better. It's bright enough as it is anyway. I'll just use the lower wattage ones for the rooting part then switch to the 100s.

You could probably use these bulbs for flowering too, if you had enough of them, like 4 per sq ft. It's actually cheaper than diy COB lights, about 50 cents a watt. The only downside is that you need a bunch of lamp sockets unless you solder the wires on or make some kind of special clips. Another advantage is that they can't all burn out at once and you can quickly get replacements if they do.

I have had great results flowering with 12.5w feit omni bulbs...got about a gram watt(no diffusers). That was running about 70 watts per square foot, growing short single cola plants. You're right though the cost of sockets makes the price jump a bit. I've since switched to cobs.

grow1620 said:

I have had great results flowering with 12.5w feit omni bulbs...got about a gram watt(no diffusers). That was running about 70 watts per square foot, growing short single cola plants. You're right though the cost of sockets makes the price jump a bit. I've since switched to cobs.

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I guess if it was a fair sized chamber it might help to take off the diffusers. I don't know if they actually reduce the lumen output or not. Somebody with a lux meter would have to compare the two. Maybe that's why the lumen output stated on the bulbs seems a little low for LEDs. Maybe with the diffuser off it's more like COB output. Don't have a meter myself or I'd check it. The diffusers are good for clones though, and when you have very limited vertical space.

There is a very lengthy thread on another forum devoted to these led bulbs. It even compares output with and without the diffuser. The diffuser does reduce the output of the bulbs.

tiedye_ said:

There is a very lengthy thread on another forum devoted to these led bulbs. It even compares output with and without the diffuser. The diffuser does reduce the output of the bulbs.

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Okay. Probably hard to find it but I'll try. The diffusers are good in one way though, they equalize the light from all angles pretty evenly. I can mount one sideways and it still provides good light. They're quite amazing diffusers actually. I took a bulb once and stuck a small LED flashlight up against the end of it and it spread right around the whole diffuser evenly almost like it was fluorescing. I don't think there's any phosphors in it or they wouldn't be so cheap but it almost looks like it. I'm actually going to keep them on. The lumen output is still 100 per watt, which I think is sufficient.

These bulbs are great actually. I'm adding them to my COB high bays for supplementation. I have a Y socket on each end of a 3'x1.5 chamber with the high bay in the middle. I had 23 watt CFLs in them but now I'm going to replace them with 100w replacement LED bulbs. The cfls put out 1600 lumens and the LEDs 1500, but the LEDs are only 14.5w. That's a big increase in efficiency. LED bulbs were too costly to be competitive with cfls before, but now they have these new cheap ones so it's time to take advantage.

tiedye_ said:

Google "Off the shelf retail store screw-in LED and CFL bulb comparisons". Some great info and pictures in that thread. It's pretty amazing the results possible with these screw in led bulbs. Much more efficient than cfls. Not to mention half the light emitted by a cfl is going in the wrong direction without a reflector of some sort.

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That's was A geat comparison of Cfls and Leds... I didn't expect Leds to out perform Cfls that much...
here's the link to the comparison: https://www.icmag.com/ic/showthread.php?t=314806

lordofbud said:

That's was A geat comparison of Cfls and Leds... I didn't expect Leds to out perform Cfls that much...
here's the link to the comparison: https://www.icmag.com/ic/showthread.php?t=314806

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Now that LED bulbs are reasonably priced, the cfl industry will probably collapse soon. I just wish the LED companies would put out higher wattage ones so we don't have to buy a bunch of lamp sockets. Though I guess it's better for heat dissipation to have a bunch of lower wattage ones, and also better for light distribution. Oh well, even with the cost of the sockets they're still less than COBs. The COB drivers are outrageously expensive, usually about as much or more than the COBs themselves.

I just revamped my early flowering chamber, 3'x1.5'x4', by converting from CFLs to LED bulbs. I put 10 100w replacements in and it's very bright. I wouldn't recommend more than that. The plants are really sucking it up. These lampholders are what I used, very inexpensive.

I wired them in two strings of 5. Had to break off some openings in the edges so the wires could get to the screws without having to go down from above. Just used pliers to snap about an inch off on each side, except the last ones on the strings which only needed one side snapped off. So it's the wires going in one side and hooked to the screws and then another wire going out the other side to the next one. There's 2 sets of screws for each terminal, so you can daisy chain them like that.

Then I connected the last wires from each string to one power cord wire after I had the 2 strings screwed in place. So they're all wired in parallel and there's just one power cord. It was quite a pain screwing them to the top of the box but I eventually got the job completed and it worked out great. The best thing about using the LED bulbs and lampholders is that it's cheap and you can buy all the stuff at a hardware store like Home Depot, the holders, bulbs, wire and screws. Altogether for 140w of LED, 15,000 lumens total, it cost me a little over $100.

Here's a pic showing the middle 6. Those holes in the top are for ventilation. It's a little rough looking, I drilled the vent holes after it was painted and some wood splintered off. Anyway, doesn't matter how the top looks, as long as I got the lights up there. There's mylar on the sides even though it was painted white too. A fair amount of light can pass through mylar emergency blankets so the white walls are an extra layer of reflection.

I only used 1 screw on all of the holders but one. It was so much trouble screwing the screws up under there that I settled for just 1 each after the first one. Still nice and solid though. Two different types of bulbs there, the longer ones are A21s. An extra 50 lumens from those ones, 14.5 w instead of 14. So actually 15,200 lumens total. I used 2700k ones for the most red spectrum. I used some 5000k ones for the clones for the 3 weeks of veg. So who needs COBs or CFLs, right? I do use COBs for the middle and late flowering chambers though. I'm 100% LED now. I even use a 60w replacement bulb for rooting the cuttings.

very nice job
..man it's trippin me out how much this looks like something that I would build, or have built lol. I did the exact same thing clipping off the edges to let the wires out.

grow1620 said:

very nice job
..man it's trippin me out how much this looks like something that I would build, or have built lol. I did the exact same thing clipping off the edges to let the wires out.

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What did you use it for, CFLs? Having to break parts of the edge off is pretty inconvenient but aside from that it's not too hard a job, just a pain screwing them on if the box is already built and you have to try to hold them up there and put the screws in at the same time. BTW if anyone does this be sure to wear some kind of glasses because the plastic snaps of in shards sometimes.

This setup is perfect for the LED bulbs because the LEDs inside them are pointing straight down, though the diffusers do spread it out a lot. Could cut the diffusers off but I prefer the light to be spread out more so the plants won't bleach as much. It's plenty bright as is anyway and it's all mylar on the walls so the light is all contained in there and hits the plants eventually. It might not be worth the cost if you had to buy the more expensive sockets, which are four or more times as much as those ones I linked, which were $1.29 each.

I built a very similar setup for led bulbs, 5 sockets onto a separate ceiling piece that I would attach into place. I've since refitted it with a single cob, but the led bulbs worked great for me(for bout 2 years), and I still use them for extra light in my other box. I'd link to my grow but it's on another site.

I really like what you're doing here...I think alot more ppl need to switch from cfl to led. Like you said now that leds have come down in price, cfls are on their way out the door. The only reason new growers are still starting out with cfls is because of the huge amount of old cfl info/threads out there.

grow1620 said:

I built a very similar setup for led bulbs, 5 sockets onto a separate ceiling piece that I would attach into place. I've since refitted it with a single cob, but the led bulbs worked great for me(for bout 2 years), and I still use them for extra light in my other box. I'd link to my grow but it's on another site.

I really like what you're doing here...I think alot more ppl need to switch from cfl to led. Like you said now that leds have come down in price, cfls are on their way out the door. The only reason new growers are still starting out with cfls is because of the huge amount of old cfl info/threads out there.

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They're a lot more efficient, which also means less heat. 14w LED iiiiis 1500 lm and 23w CFL is 1600 lm, so practically the same and about 1/3 less power consumption, therefore 1/3 less heat to deal with. Now I have a bag of CFLs to get rid of though.

Back in the day, before we had an abundance of LED choices to cover 2 x 4, I bought -4 bulb vanity fxtures from Lowes/HD. All I had to do was wie up the power cord and screw in the LED spot lights

PetFlora said:

Back in the day, before we had an abundance of LED choices to cover 2 x 4, I bought -4 bulb vanity fxtures from Lowes/HD. All I had to do was wie up the power cord and screw in the LED spot lights

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I considered one of those, with 4 sockets, but I needed a lot more than that and it was more costly so I went DIY. I'm also short on vertical space so I wanted the sockets as flush with the ceiling as possible. I'm happy with the way it turned out, just was awkward installing them. After I was done I had a feeling of accomplishment though.

I did eventually cut off all the diffusers. They get way too hot with them on because the LEDs are sealed in. That will reduce lifespan. The plants also perked up when I took them off. The only ones I kept the diffusers on were the ones for clones and veg, due to them being very close. I leave about 1/2" of diffuser on to make it easier to screw them in and also to catch any light that tries to go out almost sideways. It's perfect, like miniature spotlights. Fairly easy to cut through them with a serrated knife.

Have you all looked at the Quantum boards yet ? They are ideal for small spaces.

This shows the kind of growth you can get with just ten 100w replacement bulbs in a 3'x1.5'x4' cabinet, 140 watts total output, diffusers cut back to 1/2", all 2700k. The growth looks perfectly healthy. It's actually a lot brighter in reality than it looks here. I might be able to put 2 more bulbs in but that's about the maximum I would try. If a person really wanted to they could squeeze 18 in there, 252w.

I found a better way to get the wire to the lampholders than breaking off a piece of the side. They have two extra screw holes that are blocked by "knockouts", thin plastic. If you poke them out you can then just snap off a piece of the edge of that screw hole with pliers to allow the wire to go through while still being able to mount the holder flat. Those screw holes are also closer to the wire terminals so it's easier to hook the wires up from there. It's all around better. I noticed the knockouts when I decided to add 2 more lights. I think 12 will be just right, about 40w sq ft.

BobCajun said:

Okay. Probably hard to find it but I'll try. The diffusers are good in one way though, they equalize the light from all angles pretty evenly. I can mount one sideways and it still provides good light. They're quite amazing diffusers actually. I took a bulb once and stuck a small LED flashlight up against the end of it and it spread right around the whole diffuser evenly almost like it was fluorescing. I don't think there's any phosphors in it or they wouldn't be so cheap but it almost looks like it. I'm actually going to keep them on. The lumen output is still 100 per watt, which I think is sufficient.

These bulbs are great actually. I'm adding them to my COB high bays for supplementation. I have a Y socket on each end of a 3'x1.5 chamber with the high bay in the middle. I had 23 watt CFLs in them but now I'm going to replace them with 100w replacement LED bulbs. The cfls put out 1600 lumens and the LEDs 1500, but the LEDs are only 14.5w. That's a big increase in efficiency. LED bulbs were too costly to be competitive with cfls before, but now they have these new cheap ones so it's time to take advantage.

Click to expand...

There is new lights better suited to plant growth just recently swapped 2 85watt leds for a much nicer 216watt on 57 rn on Amazon and saw a substantion growth increase