crazy ph probe

[jsshark1]

Hi every one .
I got a Aqua Controller II and thought it was a good day to try to apply it to my reef system .

it was used but told that it has no problems,
I have calibrated the Ph probe with ph 7.00 and ph 10.00.
every thing looks good till I put the probe in the tank.
I almost died when it showed 6.34.
I pulled out my test kit and it shows a good 8.00.

I have two tanks on one system so I thought I would get a cup of water out of the other tank and it showed 8.10

then I got a cup of water out of the tank I have the controller on and in the cup I get 8.10 then I drop the probe in the tank and it goes to 6.3 . I have tried unplugging the other sensors one at a time but it still reads 6.30 in the tank . I have no ground probe in the tank. I have one that I tried putting in the tank and just to see if it would help but nothing.


any thought about what it can be,
Nothing but Gremlins :eek2: to me

 

[383camaro]

I don't know much about it but i wonder if there's a stray voltage in your tank somewhere. you could probably test it with a multi-meter by putting the positive in the water and the negative to ground. but you should probably confirm that with someone who knows more.

 

[ordy1]

What I would do:

Put the probe in the tank.

Shut the entire tank down.

Observe your pH reading. Did it go to normal? If it did turn everything on, one device at a time until you find the culprit that's dumping stray voltage into your tank. If it didn't make sure that everything is unplugged from the outlet and then observe your reading. Sounds like stray voltage but I have been known to be wrong.

Good luck.

Ordy

 

[diciple]

check a heater first