plant turning yellow/brown and crispy

recently turned lights to 12/12 and in the last week plants have got real bad leaves turning yellow and brown shrivelling up a fallling off . i am following a nutrient schedule form canna coco, i filll my nute tank up 100litres in tank 50ml rizotonic 380ml coco (a) 380ml coco (b) 250ml boost. heres some piks any ideas thanks

ive flushed my plants and i will use just water see if things clear up

if it's in coco, you probably need to be adding cal-mag. coco grows especially need it

thanks ill do that

Mike is right. Thats a cal-mag issue. Now the dead tissues will not regenerate, but the new growth will come in fine.

i didnt get this with my last grow and did the exact same except last plants where jack heror these ones are lemon amnesia

trust me cal-mag is a growers friend. some strains hold up to it better than others, but that is the issue. i would also get those roots covered up

been into the local hydro shop and man says you dont need cal-mag you must have ph lock i ran fresh water which i tested was 7.0 i ran through my plants catched the first drop that came out the bottom the water tested at 6.5 after i also tested my nute tank and this was ph6.5 im lost also things arent looking better

and if it is cal mag i need do i use it alongside my usual nutrients i havent used nutrients for 4 days now in case i was burning them

dampdarkceller said:

been into the local hydro shop and man says you dont need cal-mag you must have ph lock i ran fresh water which i tested was 7.0 i ran through my plants catched the first drop that came out the bottom the water tested at 6.5 after i also tested my nute tank and this was ph6.5 im lost also things arent looking better

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Was he selling you a ph pen?

If you're using soil, I doubt its a ph problem.

Dont flush either, doesn't do any good. Plants need nutrients up until the end

Ph for coco should be 5.8. Ph 6.5 is for soil. So there is probly a lockout happening because of that.

Yeah use calmag along side your nutes

sold me ph tester and ph down

damn didnt realise that yes in using coco do you think i still need cal-mag

you need to ph your water anyway, so those are good supplies. Not familiar with coco, so I can't help just wanted to chime in to help with any buyer's remorse. In my experience, with the exception of the thirty something dollar Milwaukee, the more a PH tester costs the better it will work for you and the longer it will last. My tapwater PHs at 8 after three or four days of bubbling so I go through my fair share of PH down. Good luck man.

Yh correct the ph of your next feed with cal mag.

thanls guys

dampdarkceller said:

i didnt get this with my last grow and did the exact same except last plants where jack heror these ones are lemon amnesia

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The JH I grew was a cal/mag HOG.