HELP-Mysterious shit going on, Leaf curl under + Browning/Black pistils 3 wks flower

Hi all,

This is my first post on the forum, but i've been lurking for quite some time now, gaining great knowledge off the experienced growers here.

First up, I am fairly experienced when it comes to growing mj, have done lots of grows in different mediums, soil and hydro. At the moment I am 3 weeks into flower, running a SCROG NFT setup, 4 x 600w HPS, the strains are cheese, azura and sensi-star (I think).

I've been battling a very aggressive pyth problem ever since the beginning of flower, due to ironing out kinks in the new system (this is my first grow with this system, a home made NFT).

So my first thoughts were that this is all due to the pyth problems, BUT, only a few plants in the system are acting this way. So this is where i'm confused. Half the plants look great, and half the plants don't (and they all have pyth), i'm running a steady 5.8PH with ph perfect nutes from Blue planet nutrients (their 2-part). Also, i'm supplementing with their PK product, and flairform's silika. EC is between 1.0-1.2, oh and I am using rainwater.

After trying many different natural methods to battle off the pyth, I realised it wasn't working (i'm thinking maybe my rainwater may have pyth anyway). I decided to go with chlorine, and have been dosing them at 5ppm every 3 days to try and quell the problem (for about a week and a half now). At first it worked great, I could see new fluffy roots working their way down into the channels through the net pots. But, since I am waiting for my chlorimeter to arrive, I am only guessing as to how often to dose the system (I know that at a PH of 6.0 or less you should be able to kill most strains of pyth by keeping a ppm of at least 2 of chlorine for a minimum of 30mins (a bit hard without a chlorimeter)).

So Pyth problems aside for now, does anyone think it could be anything else that's causing these issues? The lights are about 40cm from the plants, I have 2 big inline fans exhausting in-sync with an airconditioner, keeping the room between 20-24 degrees (celsius). The airconditioner shuts off when the temp hits 24, but because it is winter here now sometimes it is colder than that anyway. I'm yet to get a humidistat running the ventilation, and i'm thinking lack of humidity may be a factor.

I sprayed half the plants with bud-rot-stop about a week ago to try and introduce a bortrytis killing funghi into the foliage (bortrytis is a killer in my neck of the woods, even in winter). Funnily enough, the plants that I didn't spray seem to be doing much better than the ones I did. Bearing in mind though, that the plants that were sprayed are much taller, closer together and closer to the lights than the ones that weren't sprayed (and have always been that way).

The pictures below show the problematic plants first, and the last few are the good plants, you can see clearly in the first few pictures the leaf curl under and the brown/shrivelled pistil hairs. Because they are all being fed from the same res I am naturally leaning away from deficiencies (although it looks alot like a cal/mag deficiency) or over chlorination. Hence why I am calling it a 'mysterious' problem. I was watering them 15mins on/30mins off, but today have switched them back to 15 on/45 off in case they were being over watered. My thoughts are that this is all based on the pyth problem, and the fact that half the plants are fine and the others aren't so fine is making me think that the not-so-good plants are in a more advanced stage of rot.

BUT, i'm just not sure, so if anyone here has had any experience with anything like this before, please, some help would be muchly appreciated.

Thanks in advance,
CM.

Bump.. Would really appreciate some input

are you doing aeroponics? id say 30 on 30 off m8. hydro dnt stay dry that lng so id say it closer to half and half

also make sure that your waters flowing or bubled. try mist plants when the roots are out of water 2. interesting though

Hi mate, thanks for your reply. Things are a lot further down the track now, managed to get everything back on track, still have some leaf curl under and the foliage that was looking bad hasn't changed for the better or worse, but the plants are growing decent sized buds, pretty comparable to past grows for their age (about 2 weeks off from finish) so i guess they have been concentrating on flower production more so than trying to fix themselves.

I ended up buying some Dutch Master zone and adding it to the reservoir on their maximum dosage recommendations, along with chloramine. I bought myself a chlorine test kit and have been monitoring the free chlorine levels a lot more closely, within a week or so the plants were growing fluffy roots at the ends (still looking pretty bad everywhere else though). I think my ph may have ben swinging a little more than i realised, so maybe some nutrient lockout mixed with severe root rot has caused my problems? It definitely seems like more than one issue anyway.

i had bad rot on one plant lastym. i found it oudorz n brought it in to clone. ddnt hav p.h test or much else. magnesium deficiency curled my leaves under. try sum egg shell water misted on plants 2 it balences p.h and promotes root growth 2 might help flowers if it regenerate some dead roots. ive got sumthing i need help on m8 cn u have a read and see what you think its a minor thing im just confused with strains flowering at different times and dont know what type they are to look up whats best for them. if you tell me how to post picture off a phone you might know what they are.... my thred explains better..... its called stuck on strain. in my latest threads.. would be great man

Do you have a link man?

https://www.rollitup.org/marijuana-plant-problems/539931-stuck-strain.html. i figured how to post pics too. im at start of grow and will post updates regularly.

hey dude sounds like its a late reply i just read this and going to finish the pages... anyways they looked allright dude, maybe they have a slight overfeeding, like need to add ph'd water every day or 2, also yes check your ph as much as possible. i've done 3 grows with a hbrid nft/false aeroponics home made system and now i'm doing a recirculating deep water culture, its much easier and i think works much easier n more forgiving, but that sed i still have been designing and upgrading my aero system for when i find the right plant that will work with tha set up im trying. but yea rdwc is tha shit!!! check out hightimes 2010 growers guide, master growers or what ever, its the green covered one from that year a best of an has a great article that i based my new system on.

cheers mate!

pyth will cause those issue for sure,try some microbe tea next time from the start,thats been the best for me with pyth,I had some plants looked almost ready to die,introduced some ewc tea,and back to normal in a couple of weeks,organics will feed and help create pyth when they break down ,ewc tea will take over and kill the shit,plus ewc tea is easy,cheap and good for your plants