Ph probe interference?

[najluni15]

Hi all
I'm having trouble with my ph probe. In my sump or display it reads a solid 3.02. But when I calibrated it or put it in a cup of tank water it is accurate. Also when I unplug my skimmer or my return pump from the reef angel the probe is accurate. I'm thinking it's interference or a ground loop. Can anybody help me figure this out?
Thanks
Nick

[najluni15]

Also, my ph probe is brand new and when in buffer it reads 7.0 and 10.0 respectively. Right now I unplugged everything from the relay one by one and put the probe in a cup of tank water. unplugging everything did not help. The ph probe was stuck at 6.02. I tried my code with and without my line with the ph calibration values. Here is my current code

#include <ReefAngel_Features.h>
#include <Globals.h>
#include <RA_Wifi.h>
#include <Wire.h>
#include <OneWire.h>
#include <Time.h>
#include <DS1307RTC.h>
#include <InternalEEPROM.h>
#include <RA_NokiaLCD.h>
#include <RA_ATO.h>
#include <RA_Joystick.h>
#include <LED.h>
#include <RA_TempSensor.h>
#include <Relay.h>
#include <RA_PWM.h>
#include <Timer.h>
#include <Memory.h>
#include <InternalEEPROM.h>
#include <RA_Colors.h>
#include <RA_CustomColors.h>
#include <Salinity.h>
#include <RF.h>
#include <IO.h>
#include <ORP.h>
#include <AI.h>
#include <PH.h>
#include <WaterLevel.h>
#include <Humidity.h>
#include <DCPump.h>
#include <PAR.h>
#include <ReefAngel.h>

////// Place global variable code below here


////// Place global variable code above here


void setup()
{
// This must be the first line
ReefAngel.Init(); //Initialize controller
ReefAngel.AddStandardMenu(); // Add Standard Menu

ReefAngel.Use2014Screen(); // Let's use 2014 Screen
// Ports toggled in Feeding Mode
ReefAngel.FeedingModePorts = Port2Bit | Port3Bit | Port6Bit;
// Ports toggled in Water Change Mode
ReefAngel.WaterChangePorts = Port2Bit | Port3Bit | Port4Bit | Port6Bit;
// Ports toggled when Lights On / Off menu entry selected
ReefAngel.LightsOnPorts = 0;
// Ports turned off when Overheat temperature exceeded
ReefAngel.OverheatShutoffPorts = 0;
// Use T1 probe as temperature and overheat functions
ReefAngel.TempProbe = T1_PROBE;
ReefAngel.OverheatProbe = T1_PROBE;
// Set the Overheat temperature setting
InternalMemory.OverheatTemp_write( 820 );
ReefAngel.PHMin=405;
ReefAngel.PHMax=805;

// Ports that are always on
ReefAngel.Relay.On( Port3 );
ReefAngel.Relay.On( Port4 );
ReefAngel.Relay.On( Port5 );

////// Place additional initialization code below here


////// Place additional initialization code above here
}

void loop()
{
ReefAngel.StandardHeater( Port1,781,791 );
ReefAngel.Relay.DelayedOn( Port2,5 );
ReefAngel.SingleATO( true,Port6,60,0 );
ReefAngel.StandardHeater( Port7,781,791 );
////// Place your custom code below here


////// Place your custom code above here

// This should always be the last line
ReefAngel.ShowInterface();
}

[lnevo]

Something is causing stray voltage. Can you get a meter to check.

[najluni15]

I'll test for stray voltage and see. It must be one of those two pumps. Or both.

[najluni15]

So I tested my gfci for ground and it is grounded. I then tested for stray voltage and found only .1 volts. I then added two grounding probes to the tank hoping it would help aND it didn't. Any other ideas? Maybe it's just the magnetic field of those pumps? But that wouldn't explain why the reading if the probe is in the display wouldn't work.

[cosmith71]

I had a similar issue with the same symptoms. Turned out to be a bad probe (cracked insulation, I suspect).

--Colin

[najluni15]

Thanks for the reply. That's what I initially thought so I ordered a new one and the new one is having the same issue. The new probe calibrates fine and reads fine if I put it in a cup of tank water.but if it is in the tank it doesn't read correctly.

[cosmith71]

Is it submerged? Try putting it in the tank with the top out of the water.

[najluni15]

The top is out of the water in a probe holder

[jsclownfish]

I have this same issue when one of my flow meters starts to go bad. The pH meter is a quick indicator that one is going bad as even a small voltage leak causes the pH to drop quickly. If you simply start unplugging the potential offending instrument, you should be able to see it jump back up.

-Jon

[lnevo]

Also float switches could cause it too.

[najluni15]

Ok. I did a big water change etc on my tank today. I reset reef angel and immediately the ph went up to 6.7 (still wrong but closer). The protein skimmer was the only thing off at this time. As soon as the protein skimmer turned on the ph dropped down again. Now when I turn off the skimmer shouldn't the ph raise again? It seems to get stuck at the same number even when I restart the reef angel.

[jsclownfish]

It can take a little while for the pH to climb back up. For instance, when I calibrate I leave the probe in the calibration buffer for 5-10minutes to allow it to settle in.

Jon

[tmoore103]

Was this issue ever resolved? Sounds really similar to an issue I'm having.