Issues with coir and LED lighting

[ShowMeTruth]

Hey all!

This is my third grow. Second indoor attempt. I'm using pre flushed coir with approximately 30% perlite. Have a 4x4 tent with 2 Meizhi 600 watt LED lights. Growing Gorilla Glue photoperiod and plants are about 5 weeks into grow. For nutes, using Advanced 3 part PH perfect, but not the coir variety. Temps are between 73• and 78•, lights are on 18/6 still. Have fans keeping the air moving, no signs of mildew or anything.

But my issue is that the plants always seem to be running low on Cal/Mag. I'm using GH Cal Mag in every other watering along with nutes. I water plain one time, then nutes the next time.

So, here's my question....Or questions, really.

Would a COB light help the plants to get the right frequencies and allow for better nutrient uptake than the LED lights I have?

Or would supplementing one of the LED lights with an HPS give me better nutrient absorption?

I really wanted to stick with LED's because of the heat issues with HPS, but I'm having to flush every week or 10 days and that is NOT my idea of easy.

Secondly, would top dressing with pasteurized worm castings possibly help the plants do better under LED?

And if I am understanding correctly, when you begin to amend coir with other soil enhancements, you are basically switching to a soil grow. The reason for pasteurizing is to kill bugs and fungi. I have my own red worms and plenty of manure choices as well.

I've read tons about issues with coir grows, usually using too much in the way of nutes or overwatering. But it seems to me that coir combined with LED might actually be more of an issue for a new grower.

Is soil and LED easier for a novice than coir and LED?

The leaves are showing calcium issues and possibly a little nitrogen deprivation. Still growing well, but the lower fan leaves are showing some yellowing.

I took ten clones off the originals and all have taken root well and are doing fine. I'm an experienced vegetable gardener, but as you well know, this is a little different! Thanks for any input. As you can probably tell, I am leaning to the lights being my root issue.

 

[MrFortwenty]

Light and medium are not really related. Without seeing pictures, is it possible you're seeing light stress? That can look like a calmag or N deficiency since you are feeding them that already.

 

[ShowMeTruth]

I'll try to get pics to upload. On satellite internet and it is a ridiculous thing with uploading pics too often.

I don't think it's light stress because the presentation of the yellowing is on the bottom leaves. But I'll get pics and hopefully that will help to show the issues. Thanks!

 

[MrFortwenty]

Yeah not light stress if it's starting on the bottom. PH possibly.

 

[ShowMeTruth]

I'm keeping the PH between 5.5 and 6.3. I am however using cheap pens. And I got the calibration fluid from GH, but I do have to calibrate quite a bit, so that could be an issue. When I calibrate the pens, one always reads lower than the other, so I take the average between the 2 as my probable PH. Not sure that it matters, but the nutes I am using are the PH perfect trio from AN.

Is there actually a fairly affordable and good PH pen?

If it's PH, I'm going to go crazy. It's like a continual nightmare with PH here. We have high mineral content well water that runs between 7.4 and 8.2. I bought a cheapo RO system and am actually using a 50/50 combo of RO and waste water because straight RO caused problems. Or I use rain water from a collection tank we have.

Waiting on pics to present themselves.

 

[ShowMeTruth]

Okay. Here are a few pics. Apologies for them not being the best. There is some washout of colors, but you can see the mottling on one leaf and the yellowing on another pretty clearly. No idea about what caused what looks like a critter chomping on the one yellow leaf. I haven't seen any bugs other than one or two fungus gnats.

 

[Ennui]

The forum likes to protect its sponsors, and rightly so, so put this in the search engine of your choice and see what you find. I'm still new and feeling my way around re; rules.

"marijuana plant problems and cures"

Look for links with pictures and explanations of the various maladies.

 

[Ennui]

Okay. Here are a few pics. Apologies for them not being the best. There is some washout of colors, but you can see the mottling on one leaf and the yellowing on another pretty clearly. No idea about what caused what looks like a critter chomping on the one yellow leaf. I haven't seen any bugs other than one or two fungus gnats.

You need to put the plant in natural light completely out of the LED. Or just switch the light off few a couple of ticks and use a flash. Plant will think it's a cloud.

 

[ShowMeTruth]

You need to put the plant in natural light completely out of the LED. Or just switch the light off few a couple of ticks and use a flash. Plant will think it's a cloud.

Okay. I'll take some more pics that way. I've been through a few different "problems with pics" and from those, it looks like calcium/magnesium and possibly nitrogen deficiencies.

I was just saying what I was using so people would know, not trying to vaunt one over another at all. Is that bad form? I can go and edit it if it is something I shouldn't do.

 

[Ennui]

Okay. I'll take some more pics that way. I've been through a few different "problems with pics" and from those, it looks like calcium/magnesium and possibly nitrogen deficiencies.

I was just saying what I was using so people would know, not trying to vaunt one over another at all. Is that bad form? I can go and edit it if it is something I shouldn't do.

No, don't worry. They understand innocent behavior I just try not to make it a habit, I hang here often as of late.

 

[ShowMeTruth]

I got a new phone, but it has a crappy camera. I hope this is helpful.

 

[ShowMeTruth]

Any thoughts? Specifically to the issue of LED light with no green spectrum and to a reliable decent and yet affordable PH pen?

 

[MassMedMan]

Adding perlite to coco is part of it. That's just making those young plants have access to more water. Meaning you feed less. No perlite and they'll dry a bit faster.

I think you're on to something with the Leds and temps. I ran leds only, with soil only. When I switched to coco I had leds, a couple CMH lights, and an HPS in the room. So, it was warm and my plants drank everything I gave them.

Those are young plants. See if you can raise the temps a bit, that may help them take up more. But, once the root system develops that'll happen anyway.

I wouldn't use anything with coco. Just my two cents.

Good luck, stay lifted!

 

[Mars Hydro]

Plants under LED grow lights, no matter COB or tradional led grow lights or quantum boards, will all have the cal and mag problem, you need to feed them more on this.

 

[ShowMeTruth]

Any idea as to how much should be fed? And should I include it in the plain water waterings? I've been alternating between nutes and no nutes on water. Should I just include Cal Mag in the plain water?

And with LED, have you (or someone you know of) found that adding green helps with nute issues in coir?

 

[MassMedMan]

Plants under LED grow lights, no matter COB or tradional led grow lights or quantum boards, will all have the cal and mag problem, you need to feed them more on this.

Never been my experience, Sara. On the cal mag. Not with doc's kit, not when I ran house and garden, or RX green solution. I don't own cal mag. Not, even for my tomatoes. But, that's just me.

 

[ShowMeTruth]

MMM, just looked at a journal of yours, and beautiful work! But it was all soil with LED. I have to get more familiar with the site... Are you doing coir with LED?

What I am hoping to do is a perpetual grow with this GG#4. I do much better with things if I do them everyday and not just here and there.

So, should I give CalMag every watering? And should I try to stick to 5.8 on the PH?

 

[bunkbudz]

Hey truth, I’ve done several coco perlite grows under led the last few years and have always seemed to have a cal mag issue. I always fed nutes with cal mag at every watering at 5.9 ph and still had what appeared to be a cal mag deficiency.
I even tried to up the ph 6.2 in flower to try to make the cal mag more available but still had issues and never really found a solution. That being said the growth rate and the finished product was still excellent growing in coco but I’ve recently switched back to soil just so I don’t have to hand water daily.
Sry for the lengthy rant with no solution lol but hopefully someone who has experienced this can chime in.

 

[CareStaker]

LED isn't a quantifiable spectra, so LED =/= X spectrum. After running more than 7 brand of LED, in my experience, most LED panels DO require extra Ca. Light spectrum in relation to media, matters too. I know I have white LED in flower, but not too much (red) 660nm, so I know I'll use a little extra Ca in a 80/20 soil to coco mix. I won't stock my pot to have more than I need. If I ran blurple LED, I'd stock it with more. If I were using blurple LED and coco, I'd use even more still, to amend my mix with. It ALL matters - if it matters at all when you consume it.

Looks to me that you might be using city water, or demineralized water. Run the Ca/Mg at every watering if so. If not, try adding some dry Ca/Mg as a top dress. I use Elemental by Roots. This will raise your pH, so your inputs while it is present on the top of the coir, should be at the lower side of correct. They just look slightly hungry.

 

[ShowMeTruth]

Hey all! Thanks for the replies!

We're on well water. High lime and a little high in iron. PH of well water is between 7.4 and 8.2. So high. I'm using the "waste" and RO water together. The waste is filtered, just not as filtered as the final RO. Or I use rain water.

Today, I have basically been going to school on this grow log. It truly does seem that LED and coir have issues whereas HPS and coir do better.

Alien Hydroponic EasyFeed System

I'm halfway through and have like 6 pages of notes already! lol.

I'm thinking of just getting one HPS light for my 4x4 tent. I'm really just concerned with temps, but can probably figure that out with some ducting.

Perhaps people with water that isn't naturally too high in minerals can get better results off of LED and coir. But this plagued me my first grow with calcium issues, and outdoors, I had no problems with mineral issues. Even watering from the well with no PH adjustments whatsoever.

Mind you...I am small and new, and always know that no matter how many books you read, the plant or the animals don't read that book so they act differently in each different environment. There's no teacher like experience.