Hi, I would definitely like to see the PH of the run off and the PH of the nute solution. If you can a PPM reading for both is also very helpful.

You want your PH slightly acidic at a PH of 5.5 to 7.0
Runoff PPM should be 800 or less.

I think since you are using FFOF there is a ton of information on suggested GH FFOX feed schedules out there already. It might do some good to hunt around and see what nute schedule other growers use with this mix.