can you do a runoff test please?
make your normal solution .( it must have all 12 minimum mineral)
measure ph and ec .
water until there is runoff .
measure ec and ph
the necrosis ( dead tissue) is a sign of light damage but at the top not running down the plant.. if you can do a wee bit of an over flow we can at least rule out too high EC in medium.
it should not be higher ths5 50% more than feed
if feed is 800 then runoff shud be 1000 to 1200
if it is 2x or eg 1600 th4n its nutrient lockup and burn.
need 5o over water medium with normal solution ( not pure water ) to push out older solution and replace with balanced new solution
if not the plant got a little extra water and you can rule it out .
if it is it you just fixed it.
not a lot to do about high ec or deficiency other than flush old solution and replace with new fresh solution. solution is cheap..if you replace one or add a supplement to might as well replace or add all . nutient is cheap the plant and your time is not
Thanks John for your reply!
Please kindly note that I'm living in Tunisia and I can't even import the necessary tools to measure EC and PH (lot of questions and customs agents open the parcels). In other words, I can't do the measurements.
But I want to tell you that I alternate between sun and artificial lights (November is sunny and hot 23-26°) and I remember that there was a windy day, do you think it's maybe a wind burn problem?
