I would guess its your organicare! Those long term release nutrients can mess with your feeding schedule. Also, they need to be mixed throughly in the soil, rather than in just a layer. That way the roots don't burn up when they hit that layer!

Also if the ingoing ph is 6, and the outgoing is 5.0, your soil ph is 5.5, which is too low, not to high. The layer of ferts might be messing up your readings there. Where did the 7.0-8.0 readings come from?