First grow, I need help with unwell plant!

[Waira]

good water!... but that r-o ppm of 2000 is high,... I'll ask a couple coco-nuts about this,.. what was your feed ppm's before? In any case, if it's halted, that's what matters most! But we don't want high ppm/salt build-up to start other shit going, so let's see what the coco savvy have to say,...
the TDS meter is in good shape, calibrated or at least checking out OK on other solutions you have ppm confidence in?