Coco Coir, New Leaves Yellowing And Have Brown Spots

[xinobyte]

1. Are you growing from seed or clones? Seed
2. How old are your plants? 15 days old
3. How tall are your plants? First node
4. What type of hydro system are you using? Handwatering Canna Coco
5. What brand/type of nutrients are you using? MaxiBloom + calmag + silica
6. What is the Ph of your nutrient solution? 5.8
7. What is the PPM/EC of your tap water? 165 PPM (.5)
8. What is the PPM/EC of your nutrient solution? 500 PPM / 1.0 EC
9. What is the temperature of your nutrient solution? Room Temperature
10. Does your PPM/EC show a rise or fall when you do your daily PPM check? Rise mostly
11. Does your pH show a rise or fall when you do your daily check? No
12. Do you foliar feed or spray your plants with anything? No
13. What kind of lights do you use and how many watts combined? (HPS, MH, fluorescent, halogen, incandescent "plant lights") MH 400w
14. How close are your lights to the plants? 15inches (air cooled)
15. What size is your grow space in square feet? 3x3
16. What is the temperature and humidity in your grow space? 24c, 60% humidity
17. Have you noticed any insect activity in your grow space? No, yellow traps are clean
18. How much experience do you have growing? 2 grows

My seedlings are showing signs of calcium def but I've been feeding them calmag daily since day 1 so it can't be that. My PH is at 5.8 like suggested so that can't be it either. Temperatures ? They're perfect and so is the humidity.. Overfeeding ? I doubt it, i started feeding at 1.0 EC two days ago. Light burn ? The reflector is air cooled and it doesn't feel warm when placing my hand above the plants. Salts ? Unlikely, they're in 500ml solo cups and i'm feeding each one 500ml a day.

The only thing out of the norm is my PPM, the runoff is always higher than what i put in.
Even when i'd only feed them calmag and silica, the runoff PPM would go up daily.

I need some help, none of this makes any sense.

This is a picture of #2 on the grow log but all of them are turning light green/yellow.
Day 14 is when i started feeding everyone.

 

[Badrice]

The major red flag I see is your tap water having such high PPM, most nutes for coco and hydro require you use RO. You could have something in your tap that is causing your nutes to lock out. Thats where I would start.

 

[xinobyte]

I'm renting, RO is not an option for me.
I'll switch to distilled water tomorrow, maybe i'll have more luck with it.

 

[xinobyte]

3/4 seedlings drank their water from yesterday, looked darker and grew a bit.
#2 is stunt tho, it didn't drink anything and can't stand on it's on.

I flushed them all with distilled water at 5.8 pH and 345 ppm anyway. Same ratio as yesterday but, 200 ppm less.
The runoff is now between 375 and 390, i flushed several times but couldn't get it lower.

Maybe they were just starving and it will sort itself out..

 

[MidwestToker]

Ditch the cal-mag, Maxi already has enough cal in it .

 

[Daikokuten]

I'm renting, RO is not an option for me.
I'll switch to distilled water tomorrow, maybe i'll have more luck with it.

There is nothing wrong with your tap. 165ppm is 15 above ideal, for any medium. Coco has a million myths around it but behaves like peat that holds more air. You shouldn't be adding calmag on top of that though as that 165 is mostly calcium and magnesium carbonate(cali magic). With RO, you add that back typically anyways! Feed with a lot of runoff to prevent salt buildup. I usually feed plain water then food every few days or sooner if necessary. Like, put a lot of tap water through for you, then feed with a little bit of runoff immediately after. Your tap water is ideal.

 

[crimsonecho]

Can you post the pics of no.2, it may have something else. Maybe damping off or something. Why would it not stand on its own, is it too stretched out?

 

[xinobyte]

Here is #2, it's not stretched but very weak and won't drink.
I had to strategically place dirt around the stem so it wouldn't lay on it's side completely.

When i woke up #3 looked like this, twisted leaves and magnesium def ?
I'm pretty lost at this point.

 

[MidwestToker]

Are you using the Maxibloom while vegging ? That's a fairly high P-K ratio for those seedlings and lacking in N for the stage of growth those are in. 500 ppm of your tap and the maxibloom. Those should be around 300 ppm including your 165 ppm of source water. I run RO and max my nutrient at 600 ppm (1.2 ec) in full flower running maxibloom.

 

[xinobyte]

Are you using the Maxibloom while vegging ? That's a fairly high P-K ratio for those seedlings and lacking in N for the stage of growth those are in. 500 ppm of your tap and the maxibloom. Those should be around 300 ppm including your 165 ppm of source water. I run RO and max my nutrient at 600 ppm (1.2 ec) in full flower running maxibloom.

I ordered some canna coco a + b and will ditch everything else when it arrives.
I'll get those numbers back down to 300ppm in the meantime.

 

[Daikokuten]

Feed just your tap, 165 +150 of maxibloom only. I feed seedlings up to 350 but burn some. I only grow cuts i know in one room and a bunch of seed plants in the other. I feed the seed plants 350ppm with half being calmag, and usually about 10-15% will have small burn but nothing delaying growth or more noticeable than a tiny yellow tip. Run through a litre of tap, then run through 500ml of your ~310 solution. Do that until they're larger. You can lower the litre of tap to less after the first time you do this. Basically pour tap in until it runs right out the bottom then feed your nutrient solution with enough runoff to replace that water.

 

[MidwestToker]

I ordered some canna coco a + b and will ditch everything else when it arrives.
I'll get those numbers back down to 300ppm in the meantime.

Maxi will grow weed just fine, not my favorite but does a good job if you don't over feed it to the plants.

 

[Mass Meds]

Those plants should be loving MaxiGrow. Our plants exploded from the place you're at. I never use clear cups, are those smaller than solo cups? We would just mix-up a 1/4-1/2 strength gallon batch, and pH it for around 6.0, and feed every couple of days once the soil is dry. And the little plants really took off.

Yeah you can add soil up higher if you want. That will help support them as they are top heavy at the start.

 

[xinobyte]

Any idea what that is ?
The runoff ppm has been 300 for 2 days now but this symptom keeps spreading and getting worse.
At least they're drinking their water in half a day now, that's something i guess.

 

[Daikokuten]

Any idea what that is ?
The runoff ppm has been 300 for 2 days now but this symptom keeps spreading and getting worse.
At least they're drinking their water in half a day now, that's something i guess.

View attachment 836684 View attachment 836685

It's the progression of the burn. Being a foliage plant cannabis does not repair leaves with this level of damage. She's using them now because she has to, but she will shed these in favor of new leaves when she can afford to. Continue feeding with lots of runoff like i said at your 300 solution and she will start to take off. If she's drinking fast, shes happy with your solution and working hard to grow up. It is a little bit of a dance but keep a close eye on her top at that size. If those new little leaves are perky and progressing daily, she's happy.

Don't overthink it. She has enough nutrients for a couple days at that ppm, maybe longer even. You're providing her the food at her roots that she needs at a light rate. Let her do her job now. She just needs a daily amount to use and you're providing that. Think of it like tools to her, not food. Her light is her food.

 

[TerpyTyrone]

Is your water coming from the city or a well? The city water around here has chlorine in it. Just saying . if so let it aerate for 24 hrs before adding nutrients or they will be nullified.

 

[Daikokuten]

Is your water coming from the city or a well? The city water around here has chlorine in it. Just saying . if so let it aerate for 24 hrs before adding nutrients or they will be nullified.

Uh, that's not true at all. The chlorine doesn't affect your nutrients and there isn't enough of it for a reaction or anything like that. It CAN kill microbes, but doesn't "nullify" nutrients in any way..

 

[TerpyTyrone]

Uh, that's not true at all. The chlorine doesn't affect your nutrients and there isn't enough of it for a reaction or anything like that. It CAN kill microbes, but doesn't "nullify" nutrients in any way..

Hmm. I guess ur right. I am mistaken..thats what I get for listening to a hydro store employee. Haha thanks @dailybudz

 

[Daikokuten]

Hmm. I guess ur right. I am mistaken..thats what I get for listening to a hydro store employee. Haha thanks @dailybudz

Don't fret. Are you an all organic grower? If you were using a no burn, all organic nutrient without any salts, killing microbes could effectively starve your plant. It's not scientifically sound to say that that would absolutely happen, but it absolutely could. He may have been speaking from that angle for whatever reason. Also, the most important thing you can learn about growing cannabis is how to separate yourself from your learning. Being objective pays exponentially in this game(imo obviously). I applaud you for being able to even call yourself wrong in a place where plenty would have told me to f off lol.

 

[xinobyte]

The problem was the solo cups..
Not enough drainage, the water would just sit in the cup and the holes were clogged with coco coir.

When i transplanted them into their final 2 gallon smartpot the runoff was back to 550 ppm.
It took 10 gallons of water but it's actually 300 ppm now.