Plants dying

don't try to water on a schedule. Water based on need. that'll keep a wet-dry cycle, which will help prevent root zone issues and pests. Wait for top 1" to dry.. learn weight at that point as well as saturated after an irrigation. An irrigation should have 20% excess runoff that you toss anywhere else - lawn, drain, garden.. etc. if coco coir, maybe wait for top to change color and not so deep as soil. trying to micro dose with coco coir always had an initial boost, then a slowdown for me. ymmv, but i'd suggest treating it similarly to soil. depending on pot size, you may have 7-10 days between watering/fertilizing early on, then 2-4 days late in bloom. let the weight of pot and dryness dictate.