i am trying this coarse cocos /chips atm too.
thinking its way less salty then cocos pith and mine was very easy to wash.
problem with cocos is often the releae of a lot K when it dries, the fibre simply contains lots of it.
K have a single charge and is released everytime it got replaced by a doubble charged mg or ca.
this can be a good thing later in flower, otherwise it often cause problems if not taken in to account.
well the cocos chips really cant be overwatered so giving them a good flush cant hurt.
runoff shouldnt be higher then 0.2 more to hats going in.
dont think you need to go down to EC 0.4, 0.8 should also to.
i never needed a EC of 1.5 at this stage, 1 to 1.2 should normally do well.
dont go too high with the basesalt would say, give more calcium nitrate as the meidum eats some of the calcium and the cocos provides lots of K anyway.
you have quite some factors in to play when you have dunked them in nasty stuff recently, maybe thats simply the cause of the burns.
while, consider also.
what you captured with the lux meter and converted can be way of.
sensitive young plants i sometimes just give a 200ppfd and even less, just as much that they dont stretch to the light and have a easy life.
your cuts there really dont look like theyre after heavy growth atm, looks to me they want to root out a bit and then grow for you.
so going easy on them now is may a good idea, think its quite important to start them slowly in a new enviroment.
its maybe a combination of several factors.