pH or EC Shields/Stamps

I am trying to go about building an indoor gardening controller (like Billie's), however, my situation has me controlling 7+ different reservoirs, thus the want(NEED) to have 7+ different pH and EC probes. As I understand it now, the shields and stamps I've seen advertised will only take readings from one probe. My question is can these shields be ported out in such a way that would allow for a single shield to control 7 different probes? I am hoping a sensor shield could be used to expand the EC/PH shield's ability to work from more than just one probe.

If yes, please share anything that will get me headed in the right direction.
TYIA!

Do you have a link(s) to the things you are referring to?

Scientific Atlas makes a nice shield for EC, pH, ORP etc, and if I hit too many more brick walls on this topic, I will have to look into that inline option, but just from first glance, pumping nutes from reservoirs A, B, C, D, E, F, G and likely H and I would make for a pretty elaborate plumbing manifold, as many water pumps/peristaltic pumps, solenoid valves and return lines just to get a reading.

On the other hand, most of the higher end EC and PH wall mount controllers stay in the solution nearly indefinitely save for the occasional cleaning and calibration just to verify each probe's functionality, so I know there are probes that can handle constant immersion.

EC Shield 1

EC Shield 2 -> EZO™ Conductivity Circuit | Atlas Scientific

pH Shield 1 -> http://www.robotshop.com/en/bnc-ph-sensor-shield-arduino-assembled.html

pH Shield 2 -> EZO™ pH Circuit | Atlas Scientific

My goal is to only buy one shield or stamp, and build around it so it can be fed a signal from several different probes in sequence. So instead of reading Probe A every 1000ms, it will read Probe A, then the next signal is received from Probe B, then Probe C etc. I don't know if what I hope to accomplish is electronically possible, but I am understanding that these shields are designed to be feed a voltage down through the sensor(probe), monitor the condition of the voltage that returns and interpret this into the EC value or PH value that is then populated onto the serial monitor through the Arduino. So I am hoping that each shield can be manipulated through circuitry to function solely as a processor of the returned voltage send the findings to the Arduino.