First grow using coco and boy has it been a learning curve especially with EC and PH. I initially was way over on my EC by mixing nuets at manufacturers directions and trying to maintain a PH of about 6.0 to 6.2 with my tap water being real high on the Alkaline side. I was concerned with the amount of PH down it took to bring it down to those ranges and it's effect on my plants along with its high EC readings before adding any supplements to my fertigation. I have a 1 acre fish pond I had excavated about 10 yrs back and took a sample to measure the PH and EC readings. To my surprise it was 6.9 ph and .0467 ec which allowed me to use more commercial nutes and supplements and about 1/4 of the PH down I was adding to my fertigation on a daily basis at about 30% runoff. At first when checking both ec & ph with my tap water runoff it didn't take long for the ec to skyrocket when going in during veg at 1.450 on the us/ms scale to 1.950 quickly in runoff at 15%. I think coco is a great medium but do your homework if like me you have never used it it offers no room for fertigation mistakes or at least very unforgiving. Maintain a good Ec of about 1.200 to 1.500 in veg and no higher for me of 1.600 in flower has proven a good range on the us/mc scale.