MarkT:
No, that's one thing to avoid - putting voltage regulators or DC-DC converters in parallel
on the outputs is a recipe for disaster, use a single device that is up to the job - in parallel
you've started a battle or left one device doing all the work anyway.
do you have any suggestions how i can isolate this probe from the interference from the pumps besides removing the pumps, using batteries. surly there is a way to do this? i have a ground rod in the water with the pumps. when i measure the water with a multimeter i get 0v current flowing through the water. however if i put the meter in (Hz) i get 60hz from the ground wire of the probe? i know the probe is really high impedance so im not sure how i could filter the signal of the probe before it gets to the op amps?