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PH unstable
Posted: Sat Feb 06, 2016 9:37 pm
by Lionfan
My pH seems to be really unstable.
Even in a glass of tank water it will stay at 2.02.
When I go into the pH calibration, it gives me a 0 for the reading. And then sometimes it will bounce back to 8.23 (Normal tank pH)
New probe and relatively new RA plus.
Re: PH unstable
Posted: Sun Feb 07, 2016 4:03 pm
by rimai
If pH readings are showing zero when calibrating, there is something wrong. It should never be zero.
I have seen it before when a defective temp probe was causing ph readings to show zero when calibrating.
Can you check is this is your case too?
Re: PH unstable
Posted: Sun Feb 07, 2016 9:16 pm
by Lionfan
rimai wrote:If pH readings are showing zero when calibrating, there is something wrong. It should never be zero.
I have seen it before when a defective temp probe was causing ph readings to show zero when calibrating.
Can you check is this is your case too?
Good idea. I will definitely check temp probes.
Re: PH unstable
Posted: Sun Feb 07, 2016 9:33 pm
by Lionfan
rimai wrote:If pH readings are showing zero when calibrating, there is something wrong. It should never be zero.
I have seen it before when a defective temp probe was causing ph readings to show zero when calibrating.
Can you check is this is your case too?
I unplugged everything from the head unit, except for the power supply and waited for about 10 minutes, nothing changed.
Re: PH unstable
Posted: Tue Feb 09, 2016 6:06 pm
by rimai
Humm. Not sure what is going on then.
If you short out the inner pin to the otter shell on the pH connector in the head unit, what happens?
Re: PH unstable
Posted: Wed Feb 10, 2016 8:46 pm
by Lionfan
rimai wrote:Humm. Not sure what is going on then.
If you short out the inner pin to the otter shell on the pH connector in the head unit, what happens?
Not sure what you mean?
Re: PH unstable
Posted: Wed Feb 10, 2016 10:05 pm
by rimai
use a paper clip or small wire to short out the inner pin to the outer shell of the BNC connector in the head unit.
Re: PH unstable
Posted: Thu Feb 11, 2016 6:43 am
by Lionfan
rimai wrote:use a paper clip or small wire to short out the inner pin to the outer shell of the BNC connector in the head unit.
Will do. What am I looking for?
Re: PH unstable
Posted: Thu Feb 11, 2016 9:43 am
by rimai
What pH do you get?
What calibration number do you get?
Is it still zero?
Re: PH unstable
Posted: Thu Feb 11, 2016 9:56 pm
by Lionfan
rimai wrote:What pH do you get?
What calibration number do you get?
Is it still zero?
PH went up to about 8, and the calibration number went up to about 550
Re: PH unstable
Posted: Thu Feb 11, 2016 10:12 pm
by rimai
It seems the board is fine. It should be around 550.
Not so sure why you are getting wrong results with the probe.
Re: PH unstable
Posted: Fri Feb 12, 2016 7:56 am
by Lionfan
rimai wrote:It seems the board is fine. It should be around 550.
Not so sure why you are getting wrong results with the probe.
Ive switched between 3 probes I have, all new. Is there a chance some stray voltage has zapped all 3? One is a BRS lab grade