Yellow tops, curling in coco (still looking for solution)

[searchingforit]

I posted before about this issue. Still haven't found a solution. Treated heavily in case it was a pest issue. It's not. Not root rot either, fixed my root issue. This is nute/ph related.

Medium is coco. Strains vary but all suffer from the same problem. Growth is spindly/small. Tops are yellowing. pH going in is 5.2. Slurry test reveals medium to have a pH of 6.4/6.5. I have tried watering with pH 5.8 and this problem remains. Nutes are now CNS17 coco grow @ 600 ppm. Raising and lowering ppm does nothing.

I keep saying it is high pH issue but everyone blasted me and told me it was caused by feeding at too low a pH. Notice in second pick the black circle I highlighted. Those dots. Boron? Zinc? Iron? All caused by high ph. Water is not that alkaline and run-off is fine. Repotted, same thing. Also the edges tend to taco at the tops although heat is not an issue. Humidity is 50-60%. I've been battling this issue for months now and have tried everything possible. Haven't smoked in months now as I burnt through my stash and won't flower until I fix this. Was going on during previous flowering cycles as the quality of my bud hasn't been too good comparing it to previous grows (not using coco).

Opinions?

 

[searchingforit]

Also, purpling petioles. If medium pH is 6.4/6.5 shouldn't be phosphorus/mag but who knows, I'm stumped and frustrated. In desperate need of medicine and months away even if I fixed this tomorrow. SOB

 

[slim dog]

if you have good quality coco, your good,i use to have same problem when using pbp at low dose, correct it by up the feeding, ph 6.0

 

[searchingforit]

It is botanicare compressed. Flushed heavily then charged with cal/mg. It has been amended with rootshield (great stuff). So you're saying up the feedings AND pH? Despite my slurry coming out @ 6.5? What ppm? My tap comes out @ 150 ppm. I've been upping that to about 600 with CNS17 coco grow and feeding every day. Shit, tiny growth with spindly stems. This pisses me off because it's been going on for a while now. Last year I started with coco with this same water and did something write because I was getting ridiculous growth. Can't pin it down now.

 

[BullnAChinaShop]

The only thing I can recommend is to simplify, simplify, simplify. Don't go throwing a bunch of additives at the problem. Start with a quality coco (I use botanicare cocogro), a quality base nute ( I use maxibloom), ph up/down, and some drip clean. Feed at ph 5.8-6.1. If you still have issues after that, I would look at your water source. Do you have a water quality report handy?

I used to have all kinds of issues before I did the above.

 

[searchingforit]

It is botanicare compressed. Flushed heavily then charged with cal/mg. It has been amended with rootshield (great stuff). So you're saying up the feedings AND pH? Despite my slurry coming out @ 6.5? What ppm? My tap comes out @ 150 ppm. I've been upping that to about 600 with CNS17 coco grow and feeding every day. Shit, tiny growth with spindly stems. This pisses me off because it's been going on for a while now. Last year I started with coco with this same water and did something right because I was getting ridiculous growth. Can't pin it down now.

Yes water quality is something like:
25 ppm ca
4 ppm mg
40 ppm sodium
yada nothing special here it is relatively soft water with a final ppm of 150

sorry for dbl post was giving me trouble

 

[BullnAChinaShop]

I don't have much experience with the nute your using, but did you use this same nute before when you had success with coco?

 

[searchingforit]

I actually used KISS and had success. I then began having this same issue with KISS so I moved on to cns17 and same problem. Stoppd using all other additives to try and correct this.

 

[burns1n209]

600 is not enough, looks under feed to me. Up it to 800 to 1000. And ph to 5.8. You are at 5.2 and it could be locking the nutes you need out.

 

[BullnAChinaShop]

^^agreed.

 

[searchingforit]

My slurry confirms the pH in the rhizospere is too high. 6.5 is too high.5.2 going in should not be an issue considering the actual pH of the medium is where it's at. For instance, the plant in the picture was just transplanted into the medium. What was my initial two waterings? pH 5.8, the result is what you see in the picture.

 

[BullnAChinaShop]

I'm not sure I would trust a slurry ph reading tbh.

 

[caljim]

I grow with botanicare compressed 5kg blocks of coco and Gh micro and bloom at 6/9.

If my plants start to look like your pics my ph pen has gone too long with out calibration and was reading higher than the true ph. Calibrated the pen to read true 6.0 and all was well again.

For what its worth I dont believe your plants are under fed either, they are just locked out.

I feed GH 6/9 at 70% (4.2/6.3 per gallon) and find I get lush growth, with no lock out or tip burn, feeding daily right from rooted clone to the end of stretch.

 

[burns1n209]

I dont know to many people that rely on a runoff ph. I still think its being locked out due to ph issues. Depending on how much cal mag you added at the beginging, it could be causeing the problems. Cal mag raises my ph quite a bit. Can you flush the heck out of them with some ph water. I know 6.5 in coco is out of most nutrient range and so is 5.2. But I do understand your thought with runoff high ph, you watrr with low ph thinking it will balance out. I dont think its the case. Something possibly in the root zone rasing the ph. Like algee? Or a pesticide? Have you calibrated your pens latley? 600ppm is low for plants at that stage. 800 would be better. I know I get all kinds of defiencies with that low. Always the micro nutes I have the problem with. If your stumped beyond everything. Foliar feed them and you should see improvement in 2 or 3 day.

 

[burns1n209]

I grow with botanicare compressed 5kg blocks of coco and Gh micro and bloom at 6/9.

If my plants start to look like your pics my ph pen has gone too long with out calibration and was reading higher than the true ph. Calibrated the pen to read true 6.0 and all was well again.

For what its worth I dont believe your plants are under fed either, they are just locked out.

I feed GH 6/9 at 70% (4.2/6.3 per gallon) and find I get lush growth, with no lock out or tip burn, feeding daily right from rooted clone to the end of stretch.

What is your ec or ppm readinv when you feed with that mix?

 

[burns1n209]

Look this guy up caravaggio. Damn I hope thats how you spell his name. He was using cns17 and had same problem you did. Almost like a nitrogen problem with the pale leaves. See if he can help you. I know he ended up switching back to maxibloom but not sure if he got the problem fixed before he switched.

 

[caljim]

What is your ec or ppm readinv when you feed with that mix?

To be honest, I gave up on checking my ppm a long time ago, I just let the plant tell me whats to hot.

But the meter is still hanging there so I went and checked. My base water from the tap is 170ppm, and I add in a cap full of humic acid to every 5 gallons. That reads 780ppm on my Trimeter. The base nutes must be about 500ppm.

I do push the ratio to 6/12 per gallon (@70%) as the stretch ends right to flush.

Seems low to me also but ya cant argue with success.

As long as I'm talking, I dont see any need to precharge coco. Water in heavy at transplant and your good to go.

 

[searchingforit]

Guys come on I already said I'm using slurry method and not run off method. 600ppm (1.2ec) should be more than fine. These plants are in veg under not so intense light. Small plants show same exact symptoms. I didn't charge the coco before and has this problem, made a post, was told my pH was too low and to charge my coco. I charged it and raised pH and almost killed my plants feeding @ 6.0. Complete lockout. Oddly enough I saved them by watering with 4.0pH but this shouldn't be necessary with my water as soft as it is and the pH not drifting much inside rez.

I'm stumped. This is the first time I've seen someone claim slurry is not accurate test in coco? Seamaiden you helped me before in the "chasing my tail in coco thread". You said it was low pH too but my slurry doesn't confirm that. Note I have also foliar fed epsom saltand it did nothing. Funny enough even a complete nutrient foliar fed @ 300ppm did nothing positive so not going down that road. Need to stick to cns 17 with no supps until I get this pinned down.

 

[Mullabor]

How's the ec of your runoff? Like previous posters, i'm thinking lockout. Maybe not- could be just a tempremental gal

Had something similar. No matter what i tried she wouldn't perk up. Rite temps,ec,ph etc etc. Being summer summer here in Oz, i decided to put her outside. She'd either come good or she would be culled. Well she came good and is now in the flower room. Mother nature seemed to have fixed this up for me(thanks oldgirl)
Good luck mate, i know how frustrustrated you're probably feeling. Just keep trying new things i guess.

 

[MIway]

Dont have a specific reason for it...?... But had a bale come out 6.7 run off and wouldnt come down. Have a current bale at 5.1 runoff and wont go up... Which looks like yours, maybe was worse. Id be curious to get your runoff pH, not the slurry.

But im out to buy perlite/verm and just gonna transplant into those vs running another bale, not knowing what that pH is going to be like. Iv had bales run just perfect but letting that go and just moving past it...getting rid of the ccgro myself. Its just too frustrating.