Hi Guys
just came back from a friends grow and he's got this problem with an unknown strain, the leaves from top to bottom are turning yellow/light green, new growth from the bottom are healthy green but everywhere else is off colour, vegged for 2 months then 12/12 for 10 days so far
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he thought is was a N problem so he fed with 1.5ml flores a+ b/3.5ml veg a+ b per litre of water for a few days and nothing is improving, but not getting any worse.
flood and drain system
canna veg+flores a+b
temps betwwen 70-80
125m rvk/cf ext......... passive intakes
feeding 5ml a+ 5ml b per litre of water.
unfortunatly he hasnt got an ec pen or a ph pen yet as its his first grow

any ideas???
cheers

Darkening tips or even black tips on the leaves is a sign of a phosphorus def either caused by a ph imbalance but more likely cool temps at lights out

Owd

thanks Owd

5ml of A+B sounds sky high to me dude that would bring my EC out near 3.0 ish
I've only just started on canna nutes mesel tho so i ain't too sure..

I agree mate it could be high forcing a low ph or just locking phos out

Owd

I use canna as well, it says on my bottles 20ml a+20ml b per 5 litres of water.

gotta be able to measure the ec and ph. gonna be pretty bloody tricky otherwise...

when i was on canna i found that anything over 1/2 what they recommend would burn my plants and give very high ec readings....

Hi Leroy
your friend must get a EC and PH pen they are so important in hydro grows i think its were he is going wrong you can not guess PH or EC

I grow in flood and drain. vegged for 2 months????? crikey my full crop only takes 10 weeks to complete....

My EC is 2.0 - 2.2 and the only leaves I have dying are the very lower ones that arent receiving much light. I dont know specific ml I use but its somewhere around 150 ml of a and 150 ml of b in a 120 litre tank. I add Cannazym and Trichoderma powder too plus pk13/14 so this alters the ec level too though


if u go onto the canna website they do feeding programs to show u how much to put in. Canna aqua is better for recirculating systems like flood and drain so wen hes run out of substra go to aqua

yeah i know cheers


as low as 1/2......maybe he and i should drop the nute levels a bit, i just read the label and went by that so its my fault really
cheers



just ordered a ph pen today, gonna have to hold on the ec pen for a bit, cash flow



cheers m8