I’m using an LED for the first time (HLG 350R) and I’m hopeful some will share their experiences on how much power they give their plants during various cycles (seedling, early veg, late veg, flower). I’ve read on the interwebs that some start out at a very low wattage and then increase it with growth (possible with a dimmer). HLG customer support recommended the same. This is vastly different from an HID which is always running at max and is adjusted for height, but mostly due to heat mitigation.
What are your experiences and tricks with using them? Do you go full out from the get-go, or do you have a methodology depending on time/growth? Do you notice nutrient uptake impacted by strength?
I raise and lower the lights. I don’t like dimming. Should I lower the lights or dim or do both?..it’s easier to pick one or the other I think.
All lights are different but for mine 18” veg and 14” flower is about right. I used to try to get the light as close to the plants as possible but now I don’t sweat a couple of inches. No big deal.
The biggest challenge I’ve found when trying to balance nutes is temperature. Not TOO hot, but when hot they use more water so I dial back the nutes to compensate.
I run a Mars TSW 2000, it pulls 300 W at full power. I like having the option to dial back power. I do a combination of raising and lowering lights and some dimming at times.
Seedlings/clones, I find, prefer it dialed back for the first week or so (I go 50%) but often I have other stuff going so I want to keep full power and then I just keep them to the side or far enough away to compensate.
Mostly, I run full power after initial period for seedlings. I stay up 24”-30” during veg to get widest spread of coverage in a 4X4 tent and also that seems to be my ideal (h) for veg growth at full power. If I am needing to be closer than that during veg I dim back to 60-75%.
I shift gradually down / plants stretch up to as close as 12” for flower (that’s where they are currently, I’m pushing it a little w all the heat we’ve had. But so far so good). Late flower I attempt to drop my temps periodically, sometimes that will mean dimming back to 60-70% on really hot days.
I’ve found I can spray my foliar cal/mag epsom salt vinegar solution (and my ipm sprays as well) w lights dimmed all the way down and not damage plants, so that’s a nice convenience. I dont like spraying at night cause I’m always fighting night humidity levels.
My anecdotal experience is that w LED’s in early flower I let it get a little hotter, (as long as they have 60+% rh, 80-82 F and they seem to be happiest. I am in soil though so that may be a factor as well.
We’ve been blessed with decent weather lately. It’s not great, but heat and humidity have been modest for this time of summer. That’s one I haven’t had to worry about…yet.
Thanks for your take on this. Do you ever see any signs of bleaching or burn when growth is as close as what you have now?
That’s a lot for that light. I have been looking at one. I didn’t know the wattage. I run bp4000 at 375 watts. I also move light up and down. I don’t change dimmer. I thought about 350watts. MH 192 runs more than I like. I’m sure some of the full spectrum lights run higher also. I do have a meter to check them.
I haven’t had any bleaching or burn this round. It’s not as common w LED’s, but I have been too close in the past. I did some experimentations w how close I could get in flower and found about 12” to be my safe zone. 8-10” can stress / burn them. I would guess that this varies some per specific light output.
Your right, my recollection was off, tsw2000 pulls 300W (they say it’s equivalent to 600 HID in their marketing materials, hence the confusion). Edited previous post to reflect correction.
Your actually not supposed to dim leds. There has been lots of research on the subject and they found that dimming doesn’t just dim. It actually changes the light spectrum so because of that they suggest running them at 100% and just move it further away.
I use an app on my iPhone to measure the PAR at the tops of the plants. The app is called Photone. It’s helped take the guesswork out.
The app used to be called Korona (lol)
I have 2 x150w drivers covering a 4x4 area with bridglux 3500K LED strips. I had a lot of problems the first 4 months of use with leaf bleaching, looking like a N dificeincy running at 16 inches above canopy. I moved them up to 22 inches and now they are good.
I thought it was a nutritional problem so over fed them trying to correct it, which messed my soil up, and burned the plants even more. I thought they would have been safe at a 16 inch distance but we live and learn lol.
There are shades of your story that are similar to what I’ve recently endured. I kept cranking the dimmer down on mine until I saw what I believed to be an N deficiency. Naturally, started feeding more, but overfed. That in turn, drove up the ppm in my soil. Probably in unison, my ph dropped and I started experiencing lockout. Plants are starting to bounce back now, but learning some lessons along the way.
Full disclosure: what really prompted me to make this post was a convo I had with HLG. They explained that dimming was necessary with this light and was preferred over adjusting height. My assumption there was it had some impact to color spectrum, as their advice was to continue to crank the dimmer down until the light is at full capacity in early-mid flower. So perhaps the light emits more cooler, blue and white colors when dimmed, and more full spectrum colors with increased oranges and reds when higher? Just spitballing. There’s a part of me that says, “these guys assembled the light and are familiar with the boards. Listen to them.” The other part of me thinks, “I bought this light for the wattage and coverage. May as well max it out.”
Like you said, we live and learn. Sometimes the hard way is the most memorable✌🏻
I’ve been following the info I got with my full spectrum QB led board.
400watts max draw from power point.
Seedlings 25% @ 16" above canopy.
Veg 60%@ 16" above
Flower 100% @ 24" above.
I experimented a bit and found that heat was no problem but light intensity(burn) was at lower heights.
The light looks white right throughout the dimmer range, the deep and far red diodes aren’t bright to the eyes at any power setting.
I hope that helps.
