pete, I have been seeing some coco problems myself. I am way too lazy to figure it out, so I went back to FFOF and no more problems. It seems much more forgiving, and self sufficient. You may want to consider a ratio of 3parts perlite to one part coco. That is what Autopot Co. recommends using with their water culture pots.
Foe me though...I feel much better depending on the amendments the FFOF has in it.