Flush it if you suspect that you have salt buildup.
Coco pH should be right around 6- lower than soil- and you need to use a nute designed for coco, or add calmag to your feeding regime, or pre-prep the coco to deal with its bizarre interaction with calcium. I don't really know how to do that, and if I ever grew in coco again I think I'd go with the canna line of nutes for it. Calcium lockout is a real pain to try to treat.
Oh, and check your fert solution pH values AFTER you mix it if you aren't yet.
stinkyattic Reviewed by stinkyattic on . question on ph ? im using a set of products i got from my local hydro store im growing in coco trying to find the ideal ph for veg and ph for flowering the products im using say that they are ph stable but im getting a reading of 6.8 on both the veg and flower is this right or should i just regulate the ph anyway and go against what the manufacturer recommends ? :( Rating: 5