Seedlings in Coco Going Downhill Fast!

[LuGoo]

My runoff pH has been 6.5-6.6 and EC has been about the same as what goes in, 600-800.

Is that runoff pH high? It seems common for people to have those numbers, but maybe only those who are posting for help, haha.

I agree that it doesn't seem likely that I'm starving them, and it's been long enough of frequent fertigation without drying out, that it doesn't seem like I should be having pH problems either.

My current naive guesses:

1 - Magnesium or Calcium deficiency. Mine look similar to some pics I've seen of this problem in coco seedlings and it seems super common.
2 - Too high EC

 

[low_and_slow]

Yeah your runoff is coming out too high pH. I just did a runoff test of my cyco coco yesterday and it came out a good deal higher than I watered; I use drops and the fertigation I put in was on the orange/red side of the spectrum. The runoff came out and tested borderline green, so I'm suspecting that Cyco is wildly over-buffered for pH and is outside the healthy range for cannabis. My recommendation is to feed in the 5.5-5.9 range going forward and continue testing runoff pH and EC. You should begin seeing the runoff pH come down into the 5.7-6.1 range you need for coco, if not, then this product is garbage and perhaps we both learned a lesson about what not to buy.

Again, I've NEVER had this problem with this grow style using Botanicare or General Organics bricks, this is something new to me with Cyco...

 

[elcoloan]

I'd like to chip in. First some questions:
-What do you use to measure pH and EC? If groiwng in coco, i'd really suggest a good pH meter. Apera pH60 is a great option if you can.
-Do you have any left over coco? If you do, try to do a slurry test just to see what EC and pH you began working with.

-How do you prepare your nutes? in small batches? with MC 1 part, i'd recommend mixing up high a high concentrated solution (i dump a whole lot of MC into a 5 lt / 1.3 gal recipient), store it in a dark and cool place, and everytime you want to prepare watering nutes just take a little bit from that solution to mix with your water to reach desired EC. Also try to prepare watering nutes a day before to make sure it all settles in well and that pH adjustments and readings are more precise.

And well... If my runoff EC were that high at this point of the plant I'd be lowering the MC EC to 250-300 ppm / 0.5-0.6 EC and use this EC until runoff matches it... i think this is important especially if watering more than once a day. I'd also back up the lights just a little bit while they recover.

 

[Olderfart]

My runoff pH has been 6.5-6.6 and EC has been about the same as what goes in, 600-800.

Is that runoff pH high? It seems common for people to have those numbers, but maybe only those who are posting for help, haha.

I agree that it doesn't seem likely that I'm starving them, and it's been long enough of frequent fertigation without drying out, that it doesn't seem like I should be having pH problems either.

My current naive guesses:

1 - Magnesium or Calcium deficiency. Mine look similar to some pics I've seen of this problem in coco seedlings and it seems super common.
2 - Too high EC

In my opinion too, those runoff pH's are too high. Maybe a lot too high, it is hard to say. At any rate, I am pretty sure that the pH in your coco is out of bounds, maybe because of the stated "ph stabilization", likely lime and too much of it. I would stay away from that coco in future. You would be better off with cheap brick that you wash and buffer yourself IMHO.

As to what next with the current grow, if it was me, but keep in mind that I am new at this, I would flush with 5.8 pH, 0.6 EC nute solution until the runoff is no higher than 6.0 pH, and then continue with that nute solution while monitoring runoff. Any time runoff pH goes higher than ~6.2, I would flush again. Desperation measures, but if you can't keep that coco in bounds, the girl will not produce much. Flushing this way will use a lot of mix. My last effort used most of a laundry tub full for a couple plants, but I am using 3 gallon pots. To run this much mix through a plant, I support the plant on a screen mounted on top of a plastic tote in the laundry room, and mix up my flush liquid in the laundry tub. Actually, I use two totes so that I can move the plant back and forth while it drains so I can test runoff and get rid of it down the toilet. I could not do this in a tent or just using normal plant saucers. Bottom line is that if you flush, keep doing it until your runoff is where you want it, stopping before then defeats the purpose.

@elcoloan's idea of a slurry test with leftover coco might throw a bit more light on the situation.

Good luck with it, please keep us posted.

 

[low_and_slow]

Just did a test of my Cyco coco, the first pic is water-in (orange yellow), the second pic is the runoff, much greener (closer to 7).

It's way easier to see in daylight, but a clear shift of pH of at least .5-1.0 points is evident, this stuff is definitely over buffered.

 

[LuGoo]

Thanks for all the help!

To answer Elcoloan's questions:

1 - I use an Apera pH60
2 - TDS meter is a bobo one that came packaged with a useless pH meter before I got the pH60. It does seem consistent and in line with EC expectations per dosage info.
3 - I do have leftover coco and will run that test (huge thanks to low_and_slow for also testing!). I do remember the starting EC being super high. I ran water thru it until it was down to <200.
4 - I bailed on the per gallon mixing of MC about a week or so ago, and have been mixing up a concentrate to ensure consistency and to hit exact EC I want. I'm arbitrarily putting 16g in per L, but this stuff is having serious solubility issues. (greenleaf claims you can mix at 100x). I premix a day in advance with hot water. I usually pH just before feeding.

These ladies are at their limit in these little pots, so I'll focus on getting the EC/pH in the suggested range in the both the current and new pots.

Random transplant question: Washing perlite is a huge pain, but seems worth it given how much white powder runs off. Do you guys find this necessary?

 

[JSH1973]

I was thinking a crap Coco as well, my grow in Coco I just started is very similar to everything you do but I used Canna Coco Pro Plus and Canna Start for feed in the very beginning.
I'm going to disagree with 6.5ph being a problematic run off figure in Coco, maybe it is for soil but most run off I tested during my first grow was always around 6.5 or higher even though I always water with 5.8 - 6.0 ph

 

[elcoloan]

. I premix a day in advance with hot water. I usually pH just before feeding.
...

also try to set pH the day before using it and check it again before using.

 

[Olderfart]

Thanks for all the help!

To answer Elcoloan's questions:

1 - I use an Apera pH60
2 - TDS meter is a bobo one that came packaged with a useless pH meter before I got the pH60. It does seem consistent and in line with EC expectations per dosage info.
3 - I do have leftover coco and will run that test (huge thanks to low_and_slow for also testing!). I do remember the starting EC being super high. I ran water thru it until it was down to <200.
4 - I bailed on the per gallon mixing of MC about a week or so ago, and have been mixing up a concentrate to ensure consistency and to hit exact EC I want. I'm arbitrarily putting 16g in per L, but this stuff is having serious solubility issues. (greenleaf claims you can mix at 100x). I premix a day in advance with hot water. I usually pH just before feeding.

These ladies are at their limit in these little pots, so I'll focus on getting the EC/pH in the suggested range in the both the current and new pots.

Random transplant question: Washing perlite is a huge pain, but seems worth it given how much white powder runs off. Do you guys find this necessary?

Never done it. Didn't seem to cause a problem in any of my grows, but others here have more experience than I do.

 

[LuGoo]

Hey guys, an update...

I filled a 5gal fabric pot with my coco straight from the bag. I ran 16gal of Megacrop thru it at 400EC, 5.7-5.8 pH. Lowest I got runoff pH to was 6.41. Took forever, what a waste of time. I washed the other bags with 8gal each, and transplanted all my ladies into 3gals.

They are taking well to their new pots. I cannot believe the size of these things in just 16 days. I'm still having the same issues I started with, but it doesn't seem too impactful... yet.

I've been feeding at ~5.75pH to try to get things down, and quit worrying about the runoff, which seems out of my control at this point.

I thought my ladies looked mag deficient, and now they are starting to show clear signs of calcium deficiency too. It's very possible this imbalance is from too high pH, but it feels more likely that I just need more calmag-- a known problem as coco breaks down and 'consumes' more and more of it.

I got some calmag and I figure I'll start adding a bit to my feedings. Is this risky at all? Should I only try it on half my ladies for a while to start?

Thanks!