From what I've read, now that you are recirculating your PH fluctuation problems should improve.
Have they?
Also, do you mix your water/nute solution separately and then add it to your master res? This is supposed to help with PPm and PH flucts'.
As you know I don't run one of these systems. With my 'run to waste' hydro set up I use Canna Nutrients and they are fucking fantastic, never have any deficiencies, ph, or ppm probs.
Canna is designed purley for MJ and it contains a perfect blend of all elements.
But a run to waste system is totally different to what your using, and a lot simpler.
I know Canna make a nutrient specifically designed for recirculating systems, 'Canna Aqua', sounds like the shit you need, maybe you could look into that.
Heres a link >>>
It's still a 2 part mix but it is all you will need, no supplements or additives are really required to get great results.
You could also look at making the nutrient aspect of your grow even simpler buy using a single part nute such as 'Flora Nova', I've heard some good reports about it.
Alternatively, you could put post a thread in the hydro section and ask for what is the best nutrient to use in a water farm.
I'm sure that sort of question should get some interesting feedback for you.
I've also read that these water farms run a bit out of wack when the plants are small and it works best with bigger plants.
Hope you get it sorted.
I don't think you should look at running just water and folia feeding.