UPDATE!
Following the idea that the plants might have a nutrient lockout, yesterday I watered 1.1 lts to each pot with pH 6.5 water only. When I measured the runoff EC, it was really high, many around 2.1 and a few going even to 2.3/2.6. So, apparently I had a nutrient lockout going on.
I did a root wash until the EC was lowered to 0.7 in all the pots with pH 6.5 water. Applying 1 lt at a time, giving 4 minutes for the runoff and measuring ec with each liter. 5 lts total to each pot until they reached EC 0.7.
Apparently, the problem is that the substrate is too strong for putting clones of the size they were when I transplanted. I came to this conclusion because I didn't add more than the mychorrizae and the NPK+, that as it is organic, almost doesn't change the EC: pure water is 0.114 and when I add the fertilizer it goes up only to 0.145, which is pretty much nothing.
Any thoughts/ideas on how to continue?
Will I have to start giving it NPK+ un the next watering right after the substrate dries?
Do you think this will affect the plants production immensely?
I wouldn't like to let these go. The clones were a gift from a friend, they come from a mother he has. And on the other side, it's not easy here to get seeds to start a new crop. Ordering by mail is quite risky because as we have a special tax regime on the island, everything that comes this way goes through customs.
Thanks in advance for your help.