Hey MisterGreen- This sounds like another really cool project. If the science involved can be sorted out and a fairly accurate prototype built, maybe we can build a "Close enough Ph Controller" too.
225 Gal, Glass "Reef Ready" w/ twin Iwaki Pumps & 2 Ocean Clear inline filters. Custom 320 watt LED Lighting system utilizing a 6' Maker's Heat Sink, 12 BridgeLux Vero 18's,3 purpose built 5 channel A6211 Led driver/Controllers,iAqua Aquarium Controller
, and a 20lb CO2 system w/ Milwaukee Ph Controller.