LED feed demands

[Ichabod Crane]

https://www.alibaba.com/product-det...m=a2700.wholesale.maylikehoz.4.1120445dvvJkGs

Kingbrite is not a bad supplier. At least when I bought from him several years ago. I bought my cobs from him.

That is similar to mine. But mine is a meter long and has 450 diodes. Plus my heat sink allows me to mount things easily. No drilling of the heat sink. Just slide a t bolt in and bolt whatever you want to the heat sink.

 

[Shmavis]

Let me guess... plants looked like a mag deficiency with yellowing leaves, but didn't respond to addictional mag? If so, put some 1" thick potato slices on top of your media. Check it in 4-5 days and you'll most likely see root aphids.

Thanks Douglas for the suggestion. I cannot rule out aphids as I did have some form of pest problem with some plants under a different light during veg. But after disinfecting I saw no visible signs of bugs for either of the runs under the QB. Of course that doesn't mean they weren't there.

 

[h.h.]

Kingbrite is not a bad supplier. At least when I bought from him several years ago. I bought my cobs from him.

That is similar to mine. But mine is a meter long and has 450 diodes. Plus my heat sink allows me to mount things easily. No drilling of the heat sink. Just slide a t bolt in and bolt whatever you want to the heat sink.

I’ve been hearing good comments about Kingbrite.
I like their website because they show close ups on the lights. You can see how simple they are to put together.
I looked at strips when I bought my first lights. I think I might have preferred the strips to QB’s.
The websites I looked at were confusing and price per watt seemed high at the time, so I went a different route. Price has gone down.
I have mine set up like a rack. The QB’s are on hooks and slide. The cobs slide on the cross bars and the crossbars slide.

 

[bsgospel]

got_bud/shmavis- I like the cal-phos/soft rock phosphate suggestion from a couple pages back. Slow release, plenty of Cal, lasts a good few rounds. Gypsum would make more sense if your pH seemed to be a problem.

 

[Ichabod Crane]

I’ve been hearing good comments about Kingbrite.
I like their website because they show close ups on the lights. You can see how simple they are to put together.
I looked at strips when I bought my first lights. I think I might have preferred the strips to QB’s.
The websites I looked at were confusing and price per watt seemed high at the time, so I went a different route. Price has gone down.
I have mine set up like a rack. The QB’s are on hooks and slide. The cobs slide on the cross bars and the crossbars slide.

We should probably stop posting about lights and keep this thread on track. If you want to start a thread let me know so I can find it.

 

[Douglas.Curtis]

I saw no visible signs of bugs for either of the runs under the QB. Of course that doesn't mean they weren't there.

Correct, you really need to try the potato trick. I couldn't find them either and had the same problems. 4 days later I could see aphids running around on the bottom of the slice.

 

[Brother Nature]

Awesome thread. Have just returned to growing after a good 5-6 year hiatus and decided to go with cree COB's, coco and blumats (all things I've never tried before) and while I am quite impressed with their potential there's definitely a learning curve, the intensity of the lights themselves seemed to present the biggest hurdle for me during mid-veg and late flowering.



Let the plants get too close and they displayed what looked like nutrient deficiencies in veg, took a good week or so to figure out it was the height of the lights as temps, RH, nutrient, and ph levels were all spot on. Then let the tops get a bit too close in late budding and got some fox-tailing on one plant and 3 of 4 plants hermied (2 badly). Though it is likely it was more than just the lights as I had a few variables I'd never thrown in before (not experienced with blumats & coco, extraction fan died mid veg, super cold winter here so day/night temps were weird, had a small light leak late flowering) moving the them further away seemed to remedy the worst of the issues I had. I still will get a decent harvest and to most the buds still look and smell great, the room looks comparable to when I was running a 600w HPS, but I know they could have been so much better so I can't wait to get the setup dialed in. Lots of potential but I think there may be a few thrown off by the learning curve, I like learning new shit though so has been a great experience for me.





Here's the tent as of last night, Day 59 (harvested the worst of the hermied ones early as it was looking really sad and annoying me)

 

[Grapefruitroop]

Yes, Learning Curve is the word....or maybe Tutankamon spell...

As far as feeding for sure, and distance from light source related to the capabilities of the specific strain (adding a new variable to the big lottery of growing from seeds ) but im getting the feeling that there are some genetics that just don't like that freaking brightness!!!

Im running for the second time under LED SK602 a Julius Cesar from CC that just don't like it and look like the yellow one of the pic above....the interesting part is that the bottom lower nugs ARE nice and frosty and the top....mmmeh...not...

Im already 30 cm farther than the manufacturer raccomendation, I reached the roof and...shall I cover my canopy with a shade cloth ?!?! WTF!!! Or maybe I just have to learn how to master the proper feeding..

 

[exploziv]

As long as you don't see light bleaching on the tops you should be ok. Keep in mind that even if the tops are a little closer to the leds that you would like them to be, it just means the bulk of the canopy gets better lighting.
In my case, comparing leds and hids at about the same wattage I see better penetration with leds. So instead of having big buds just on tops, I get medium to large buds everywhere. It's a win for me, as I don't have the need or space for big hids anyway. And i can cool the leds much easier.

 

[h.h.]

I moved my lights up in my 5x5. I noticed it was only on the top canopy of the tallest plants.
Perhaps the spectrum affects the height?

 

[Douglas.Curtis]

the interesting part is that the bottom lower nugs ARE nice and frosty and the top....mmmeh...not...

Definitely back off the lights. The intensity is too much for the top flowers. What you should see are, frosty flowers on top and frosty flowers at the bottom. The only difference should be a slight change in density with the lower flowers.

Each light has a very definite "optimal light density/intensity" zone which grows premium flowers. Some led lights have limited penetration, and will do best with a scrog or sog setup. The more intense and/or concentrated the light source (cobs are an example of a concentrated light source), the deeper the penetration will be, and the taller the plants can be grown.

Have to find that sweet spot, then use canopy management to keep all your flower sites within it.

 

[exploziv]

I moved my lights up in my 5x5. I noticed it was only on the top canopy of the tallest plants.
Perhaps the spectrum affects the height?

It could also be related to the fact that imobile element deficiencies show in the top first.

 

[h.h.]

It could also be related to the fact that imobile element deficiencies show in the top first.

Could be, but it wasn’t.

 

[Grapefruitroop]

Definitely back off the lights. The intensity is too much for the top flowers. What you should see are, frosty flowers on top and frosty flowers at the bottom. The only difference should be a slight change in density with the lower flowers.

Yup, lights are hanged at ceiling that is about 8ft......I guess im gona lower the canopy level of the scrog next time, for now I moved the tops as far back as I could....I def wasnt prepared for that intensity and height problems....those fixtures are POTENT....

Thanks to all for the very interesting inputs!!

 

[MICrazy]

I'm seeing a lot of this same thing, but being a new grower I find myself in the "weeds" frequently.

My auto-girls got quite tall and they are currently maybe 16" from my lights. Running 4 OG quantum boards in a 4x4. Can't raise lights. Can't lower plants.

I did have an actual Mg def, which somewhat resolved on one plant. Her sister (same strain, different seed, perhaps different pheno, shared res, same nutes) is a yellow mess. But, the shaded leaves are mostly green.

Even now, my nubness thinks... Mag def, no... nitrogen. No... maybe a little fade. No.... maybe too much light. No.... maybe I have shitty air.

I pulled 100w out of the tent via dimmers 2 nights ago. The only changes I could see are the leaves on the yellow one turned quite purple up top.

I'm considering dimming them a little more, but I don't want to sacrifice too much potency/yield. So I dunno.

I will probably do the same thing I did last run -- drag it kicking and screaming over the finish line and hope the next one goes better.

But this thread at least got me thinking about my lights.

 

[Douglas.Curtis]

I'm seeing a lot of this same thing, but being a new grower I find myself in the "weeds" frequently.

Great post, welcome to ICMag!!

 

[f-e]

I had some plants indoors under Leds, and took them outdoors and it was crazy how the leaves kinda had a blue kinda look. You could just tell a mile away, those plants kinda kept that odd color for along time in Veg even after beening outdoors for wks

A nice dark green, perhaps too green, with a Blue tint, is mild P deficiency.

N&P keep edging ahead.

I need a 3-1-0 supplement to play with. Anyone? It's coco.

 

[Shmavis]

I start seeds/seedlings under T5 or CFL 6500K. Varying watts over the years and at one point around 200w+ but the last few years under a 96w T5 fixture or a 125w CFL. I wondered if it would help to use a QB from start to finish. Got an HLG 65 at 4000K. Supposed to be equivalent to 100w T5 or 150w CFL while only drawing 65w. I have had seedlings under it for five days now. They don’t look good. Never had babies look like this under fluorescent lighting and given their age don’t see how it could a feed requirement that’s off, but possibly. Very discouraging. The very tops are one foot from the light so I don’t think it’s proximity related. I would have them within inches under T5 or CFL. Turned the light off to get true representation.

Just wondering if anybody else is starting seeds/seedlings under LED (4000K specifically) and have found a need to change "feed" requirements. I put it in quotes because these are in FF LW - a seed starting mix - and (almost) regardless what they're in, shouldn't be in need of food at this point, right? I regularly start seeds in this mix and do nothing but water for ten to fourteen days before needing to pot up.

 

[ButterflyEffect]

I start seeds/seedlings under T5 or CFL 6500K. Varying watts over the years and at one point around 200w+ but the last few years under a 96w T5 fixture or a 125w CFL. I wondered if it would help to use a QB from start to finish. Got an HLG 65 at 4000K. Supposed to be equivalent to 100w T5 or 150w CFL while only drawing 65w. I have had seedlings under it for five days now. They don’t look good. Never had babies look like this under fluorescent lighting and given their age don’t see how it could a feed requirement that’s off, but possibly. Very discouraging. The very tops are one foot from the light so I don’t think it’s proximity related. I would have them within inches under T5 or CFL. Turned the light off to get true representation.


Just wondering if anybody else is starting seeds/seedlings under LED (4000K specifically) and have found a need to change "feed" requirements. I put it in quotes because these are in FF LW - a seed starting mix - and (almost) regardless what they're in, shouldn't be in need of food at this point, right? I regularly start seeds in this mix and do nothing but water for ten to fourteen days before needing to pot up.

Same here. I thought it was, well I didn't have a clue!

My entire veg room is LED and I've been constantly battling Mag def issues and low seedling survival rates.

I'm running Jacks Hydro, btw. I'm going to make some adjustments to the profile today and see how that plays out.

I will likely incorporate some flouros for heat and IR soon. Also adding a 315w CDM for the final stage table prior to flower.

 

[Koondense]

I use led bulbs in my veg chamber and never had issues like yours.
Plants grow normally, stay green and show zero stress.
Only trouble I had was in early/mid flowering and once in late veg but was all about too few nutrients.
Keep in mind that most seeds you get anywhere are from plants which were selected under hps lights so the spectrum differences can put them under some stress, some more some less.

Cheers