I don't think you buffered it properly. you have to soak it for 8 hours 2 times over. 100-150ppm Ca maybe 75-100 Mg? definitely not anythign that adds up to 500ppm. Its about replacing the Na+ and some K+ bonded at CES. it's about reachign equilibrium with what you intend to feed so that the ions going in and out of those CES are in proper proportion, i.e. equilibrium - so it doesn't leach anything or add anything to your fertilizer. Anyway, i don't think you accomplised that. It's too hot in there, not to mention the coco is dry AF. for 60w, it look like there is no internode, so too much light too early.. you may need new strategies across the board.