u dont need a ec meter like they say i dont use one lol i feed once a day every day at the end of 7 i flush friend of mines runs his coir with an auto feed 3 times a day every day without flushing works well for him keep ph between 6-6.5 and dont follow the nute guid well i do but they always tell u to use twice as much if u do just drop what they recamend by 1 ml been working for me