Seedlings in Coco Going Downhill Fast!

[LuGoo]

Problem: Day 7 from sprout, seedlings going downhill. Burnt leaf tips on node 2 and discolored spots on node 1 popped up in less than 10 hours. Leaf serrations pointing up and slight wavy leaves for the last few days, suddenly worsened.

Medium/grow method: coco/perlite 4:1 in 1gal fabric pots to start. Mostly Following the drain to waste cocoforcannabis guide. (I know people say no transplanting autos, but I wanted to try after issues with soil in big pots)

Feed: and supplements used: Fertigate daily at 400-500 EC of MegaCrop one part (I think v3), pH 5.8- 6.1. Feeding 400mL with 200-300mL runoff so far. Runoff pH has been 6.5 - 6.8

Water source: City tap <100ppm, rested24h+to evap chlorine (probably not necessary if I don't add any life to the medium, right?)

Strain/age: Day 7. Various strains. Pics are Blueberry Autos from New Breed Seed.

Light used: 240w Kingbrite QB. Dimmed to 70%, 29" above plants.

Climate: 78-82F, 55-70% RH

Learning a lot from this community! Huge thanks in advance for any help!

 

[Mañ'O'Green]

Problem: Day 7 from sprout, seedlings going downhill. Burnt leaf tips on node 2 and discolored spots on node 1 popped up in less than 10 hours. Leaf serrations pointing up and slight wavy leaves for the last few days, suddenly worsened.

Medium/grow method: coco/perlite 4:1 in 1gal fabric pots to start. Mostly Following the drain to waste cocoforcannabis guide. (I know people say no transplanting autos, but I wanted to try after issues with soil in big pots)

Feed: and supplements used: Fertigate daily at 400-500 EC of MegaCrop one part (I think v3), pH 5.8- 6.1. Feeding 400mL with 200-300mL runoff so far. Runoff pH has been 6.5 - 6.8

Water source: City tap <100ppm, rested24h+to evap chlorine (probably not necessary if I don't add any life to the medium, right?)

Strain/age: Day 7. Various strains. Pics are Blueberry Autos from New Breed Seed.

Light used: 240w Kingbrite QB. Dimmed to 70%, 29" above plants.

Climate: 78-82F, 55-70% RH

Learning a lot from this community! Huge thanks in advance for any help!

That PPM is way too high for seedlings 250 PPM is a good place to start. PH 5.8 going in.

It is easier to "read" the plant if you take your diagnostic pictures in regular daylight 5000K or flash, turn off the grow lights. Please.

 

[LuGoo]

Hey, thanks Mañ'O'Green! Will turn off grow light next time.

To clarify, I was using EC, not ppm, and meant 0.4 - 0.5-- Which I think should be in the range of 250ppm? I'm using 1g/gal of Megacrop, maybe a tad less, so about 1/4 strength of the recommended dose for early veg.

 

[Olderfart]

Most of what you are doing sounds pretty much spot on to me. I think you may have an issue with the coco. If your nutes are going in at 5.8 to 6.1 and runoff is 6.5 to 6.8, the ph in your coco may be too high. Is the coco amended in any way other than buffering with cal mag? Did you buffer it, or did it come buffered?

 

[low_and_slow]

Most of what you are doing sounds pretty much spot on to me. I think you may have an issue with the coco. If your nutes are going in at 5.8 to 6.1 and runoff is 6.5 to 6.8, the ph in your coco may be too high. Is the coco amended in any way other than buffering with cal mag? Did you buffer it, or did it come buffered?

This. Nothing you described sounds wrong, what brand is that coco?

 

[LuGoo]

Cyco Platinum Series Coco Coir. It's pre-washed, buffered, and pH stabilized... but I've been unable to find any details about what it is buffered with. I assume calmag.

It's been suggested that I fertigate 3x daily vs. 1x. It does make sense to me that fertigating more often would help my medium more closely resemble the EC/pH that I input, and that as the plant drinks what it wants and the coco dries, the medium would get all out of whack.

So I'm inclined to try 3x daily, and to ensure my pH is 5.8 as ManOGreen suggested. Or is the low end of the pH range best for less frequent fertigating only, where the medium dries out and pH drifts up?

Thanks everyone!

 

[Olderfart]

PH stabilized you say. With what I wonder. If lime, that is your problem in my opinion. I had a look at their website, and they do not list whatever is doing the ph stabilization.

In any case, I'm a little concerned that if you soak that seedling that often, you could run into an overwatering problem.

FWIW, I would be more tempted to flush her well with the exact nute solution you are using until the runoff comes down to ~6 pH, if it ever does, and then let her dry out normally which will take a few days with a plant that small. Fertigating three times a day might accomplish the same pH adjustment, but I think with more risk. OTOH, if the mix has dolomite in it, it will just lift its ph again in due course.

If you give her a flush, check the runoff from the first watering after the flush to see if pH has drifted back up again, if it has, the so called ph stabilization is fighting with you, and I am not sure what might work to combat it.

Good luck with it.

 

[low_and_slow]

I'm using Cyco at the moment as well, from a brick not the bagged stuff. It's been my experience as well that it's a bit 'off' compared to Botanicare which is my usual go-to brick.

In fact, I'd say I had the exact same thing happen quite honestly. I just mixed up a big batch of seedling strength nutes and flushed with the volume of the pot, basically until totally clean pure fertilizer was coming out. After that, it seems to be fine, but it's definitely not a product I'm buying again.

I fertigate my plants 4x daily as soon as I see a 5 bladed leaf. Before that, only once daily, except for the aforementioned flushing due to leaf chlorosis. At this stage I'd give those babies a wash, step back for a day or two, then see how they look.

 

[LuGoo]

Thanks for the info guys. I'm at day 11 now.

I moved to fertigating 2x a day at ~5.9pH, with >50% runoff. I've been ramping up from ~.600 EC to ~.900 EC per the cocoforcannabis guide, but have since lowered back down to .600 - .700 EC since my issues got worse.

Considering the plants are growing VERY fast and most issues showed on older growth, I assumed these little issues would resolve themselves as the plants got a bit bigger. Unfortunately, I'm still seeing issues, and it's moved to new growth.

I'm getting this bright yellowing pattern, and leaves seem harder/stiffer than normal, with deep veins. Pic attached.

I did turn on my second light, and raised both. It definitely increased the overall PAR a bit. One smaller plant in soil got a bit fried. Could this yellowing be light related? (my gut says prob not).

Got any advice? Thanks!

 

[Olderfart]

I still think you are locked out by pH or too much of something, but I do not have the experience to tell you by what, or to be sure that lockout is the issue. I do not believe that at those EC's you could possibly be starving them.

What were the pH and EC of your runoff?