ph & ec

i am on my second grow and hand feeding the plants i was gona go buy a ec meter and a ph meter but i seen a post about saying u do not need them if u use coco the coco or soil buffers the liquid is this true or shall i just go an buy the meters help wld b appreciated

PPM / EC / PH meters are the only accurate way to measure the amount of fertilizers in water.
definitely recommended, especially with coco because you need to add Ca/Mg.