How important is a dimmer on LED lights?

[RobC]

How important is it having a DIMMER in your LED lights for a limited space - 3x3x6’ tent ?
I have the impression it might be useful to avoid light burn when you can’t increase the distance due to limited height or am I wrong? Or for seedlings and clones?
Thanks 👍🏼

[SoOrbudgal]

You are correct. Which is why so many use small t-5 or a CFL for seedlings. Also depends on the watts from the wall with the LED. You don't have to worry about burning an can get them within inches of the light.

[RobC]

I should’ve mentioned that, I’m only looking at under 300w real. Nothing too big or powerful. Does that make it less probable to cause burn or other problems?

[TOKABIGONE]

Well, in my humble honest opinion, in a short space yes but if you got 6 ft, any light that would burn a seedling would be too much at any stage. I'm just saying....

[Farmbuck]

I've got two and I never use it. Just another option you pay for..!

[Farmbuck]

I'm using two Viparspectra pro series p1500 and p2000.

[MeEasy]

I don't know if it's still going on but Amazon had a really good sale on vipar the other day some of them were like 40% off

[Farmbuck]

Yeah I know. In Canada we had also a sale with Viparspectra but not anymore. I'm waiting for the XS2000 to come down. With Samsung diodes and a Mean Well drive how can you go wrong non ?

[MeEasy]

This is my third grow with my sf2000 and I just started playing with the dimmer. It just keeps me from having to move the lights as often

[PLreef]

I use mine. When starting seedlings I run my lights at 40% and gradually turn them up as they grow.

[Farmall]

Well I have used some very intense led strips and have always used the dimmer to keep the output lower. Controls the heat generated as well. I can go full output and create 110 degrees on the heat sink or about 60% and stay at 77 degrees with ample brightness for completing all growth cycles

[RobC]

How many Watts are we talking here?

[Farmall]

Mine are about 650W per unit and I have 4 unit running about 60% surface temp n the aluminum frame is about 77-78F.. 4th season in use

[ZigZag]

I love the dimmers on my lights. They are 750 watts each. they are about 16" apart, 4 feet long and 4" wide. I can use these same lights for seedlings by turning the down to <10% and hanging only about 12" above the plants. Then I raise them and increase output until they are full power, about week 3-4. I can get the lights about 7' off the floor so if I get a tall sativa and I need more headroom to avoid burning then I just use the dimmers. If your plants genetics tend to be mid height or tall then use it for sure in the space you have. could be a harvest saver!

[dropinbiking]

In a perfect world you would have a light sized for every stage of the growth to maximize efficiency, space, and heat. Having a dimmer on a quality LED pretty much turns it into any size light you want. Can bring it low down and turn it all the way down to start a tray of plants, and turn it up throughout the grow.

Ideally you'd want a dimmable LED that would blow up your grow space at full power. If so, you'd likely only be running it at about half power until early or mid flower. Save on power, save on heat, save on stress to the plants, its a win all around.

[Rwise]

I only use the dimmer to show others it works, for sprouting I run 100% @ 25-30 inches, Mars Hydro TSW 2000.

[OlderNOTwiser]

Rwise I went from a Viparspectra 450 to the Mars TSW-2000 a few months ago. I'm still burning the tops of my plants. My little tent probably is more reflective than the much larger space you're using. It probably helps if the plants are the same cultivars. My little Solomatic CBD auto is only about 9" tall (gonna be a pain to trim, looks like one solid cola) and has serious light burn issues. Another CBD auto is also getting crispy. Neither has been closer than ~ 30" to the light. My experience thus far is that the high CBD autoflowers are real sensitive to the light. (My tent hasn't topped 75F yet so it is the light not the heat) I'm just now using the dimmer. I'm finding that about 75% and 24 - 26 inches for the taller plants (Fastbuds Gorilla Auto and Seedsman Amnesia Auto) leaves the little guys around 30 inches.

To the OP, I'm also in a 3 x 3 x 6 and despite my crispy leaves I'd say get the best light you can afford, that is properly sized for your space, and if ya get a dimmer, use it or not as the growing changes the needs. I'm getting more cozy with my light now and will be using the dimmer more going forward.

[MrPNW]

Thats what I’m thinking, strain plays a big part. During veg my Pennywise high CBD hated anything closer than 30” @ 60%. I didn’t start turning my light slowly up tp a 100% until into flower.

[ZigZag]

My experience too, genetics can make a big difference in how specific plants react to various amounts of light, given all else is the same. Even the same cultivar will have plants that have slightly different requirements and tolerances. Just got to find a balance. Sometimes when I have two strains that are of significantly different heights to keep the canopy even I put risers under the shorter plants so everyone gets access to the same PPFD. You can also try watering the "crispier" ones more to keep the leaves a bit cooler, as long as they don't get too heavy and droop too much before lights out. I've done this and had good success. You just have to keep watch and make sure to check to make sure they are "perky" in the morning, which will mean they aren't drowning. You might also try placing the "crispy" ones as far from the fan(s) as possible to reduce evapotranspiration...which will help maintain water content in the leaves. Happy growing!

[RobC]

Thanks guys good stuff here learned a lot

[bboyfromwayback]

It depends on the light. Some are a lot more powerful than others

[dropinbiking]

Abode 1,000 PPFD without good co2 plants will light burn. Dimmers really do help with that.

[RobC]

Thank you all for you input, I’m learning to better choose and use LED lights

[MeEasy]

If nothing else stay away from the blurple lights RobC lighting is the most difficult to weed through because there's no real industry requirement/ standard for advertising or testing so they use words to twist the truth into a confusing mess. Good luck 🌳 😎

[dropinbiking]

Blurples were my downfall. Every new grower buys a few small blurples and always ends up trying to pawn them off at some point hahaha. Seems like china ran with the same random combo of chips in boxes with fans for like 5-6 years before ever finally getting on the wagon of making legitimate grow lights.

[RobC]

I should’ve mentioned that I’m only looking at under 300w real. Nothing too big or powerful. Does that make it less probable to cause burn or other problems and therefore less need for a dimmer?

[RobC]

MeEasy I’m looking at the HLG options, could be 2 x HLG 65 or 100, ideally the 300L (w a dimmer lol) but it’s a lot heavier and I’d have to pay a lot for international shipping on top of the price tag so probably wouldn’t spend that much to begin

[MeEasy]

dropinbiking alibababa has some good prices for lights and I've heard more good than bad about them. I believe it's king bright that a few guys have and they're pretty happy with them.

RobC I know alot of people who have hlg lights and are very happy with em. I don't like the co because of personal shit but I won't bad mouth their products they seem to be top of the line. I would go with a minimum of 100w anything smaller just doesn't put out enough light to grow quality buds.

[dropinbiking]

Yeah if you go with HLG, get nothing smaller than their 260w kit, or something similar. Just sucks you need to pay twice as much as what you pay other place.s