Calibrating Conductivity, how often?

[ToLearn]

How often should you calibrate a Neptune conductivity probe?

 

[Deleted member 143833]

Once a month is a good schedule; you should clean and calibrate all probes once per month anyway so it fits.

 

[110galreef]

Mine seems to be off quite a bit & drift a good point or two a day. I have a calibrated refractometer and got the tank at 35ppt. I ever checked against a cheapo float style hydrometer. shows basically the same.

The salinity probe value seems to drift as high as 37.3ppt in a day? what gives. The probe is only a few weeks old from a new kit.

Now I know a 250g display isn't loosing that much water over the course of the day. I am currenty topping off the 3 gals of water loss about 3-4times a day.

I have the probe in the final section of my sump, about 6" from anyother probe. It is also under (the tip) about 4"-5" of water all times.

Seems recalibration won't solve it as it drifts, not consisitently reads high.
New probe?

 

[schwaggs]

Are you using temperature compensation? Others on here hacve noticed that without temperature compensation properly configured, the salinity reading goes up and down with the tank temperature fluctuations each day...

 

[110galreef]

I don't believe I have temp compensation on. Do i just trun it on in the controler? Or do i need ot do anything else?

 

[110galreef]

also my temp only fluctuates a 1/2 degree a day

 

[Deleted member 143833]

If you don't have temp compensation you can expect the reading to fluctuate; salinity is affected by temp.

 

[110galreef]

so what do I set it to? It appears it is a value, not either on or off? Right now just has 0 in for the value

 

[Rick's Reef]

If you have no temp probe in place, then leave it set to 0.0.

See page 3 of the PM2 manual:
https://www.neptunesys.com/PM2-20104031_WEB.pdf

Good luck,
Rick

 

[110galreef]

I only have a temp probe on the main unit, not the PM2. (Temp Comp 0.0 settting) So should I put the temp probe I have on the PM2 and use the temp compensation? Can I then use the temp probe reading off that for my display and control my outlets still, if I just use that temp address?

Also the salinity swing really doens't correlate well with my temp. sometime it will randonmly jump a whole point in a 10 min period. The log shows some huge swingswithin an hr period and othing has been done or temp may have only chged .2 degrees?

To buy another temp probe seems nut as I already spent, like $90 for the module, $80 or whatever for the salinity probe and then now another $70 for the temp probe.

This is just for a probe for nothing I am using to control anything, just look at. And now it seems to be drifting all over so fortunantly it's not controlling anything

 

[aquamanic]

Yes, you can use the readings from the temp probe for other things but it must be on the same module as the conductivity probe if you want to use temp compensation. Remember, the name of the probe will change when you move it to the PM2.

 

[110galreef]

Looking at graphs it seems to jump almost a point to point and half when the lights come on & then drop another point or half after the lights go off. These are the main swings, but there are still about .3-.5 swings thru out the other parts of the day. Then usually some sort of signifigant drop to like 35.5ppt. My acctincs come on at 3:00 off at 10:00 & then MH's at 3:30 & off at 9:30.

Again temp swing is at most.5 degree. And the lights are not doing much to heat the water as the main heater is on much of the time the MH's are on as well

 

[110galreef]

Anyone know how to save a screen shot of the pH graph?

 

[Ellery]

Conductivity Probe Calibration ???

Conductivity Probe Calibration ???

Yeah I have the same problem with my Apex PM2 unit for Conductivity. I have the following setup:

1) Calibrated Refractometer with both DIY and lab grade 53 mS fluid to 35ppt/1.026
2) Checked Tank water to be the same
3) Have Temp Probe on PM2
4) Enabled Temp Probe on PM2 to ON for Temp Compensation
5) Used Default Temp Compensation value of 2.2
6) Range set for Salinity
7) Calibrated Probe Dry = 000
8) Calibrated Probe High 53000 = stabilized around 480 (but has varied a bit up to as 525 to as much as 607)
9) When completed it reads ~35 ppt on the screen while in the Calibration Fluid but drops to as low as 18-22 when placed in the sump water which was previously checked to be accurate on the Refractometer.

Kinda boggles me too. I may be doing something totally stupid. Maybe I should just use the tank water as the calibration fluid instead since it supposedly is already at 35 PPT/ 1.026 salinity already.

 

[Ellery]

Nevermind

Nevermind

Yeah I have the same problem with my Apex PM2 unit for Conductivity. I have the following setup:

1) Calibrated Refractometer with both DIY and lab grade 53 mS fluid to 35ppt/1.026
2) Checked Tank water to be the same
3) Have Temp Probe on PM2
4) Enabled Temp Probe on PM2 to ON for Temp Compensation
5) Used Default Temp Compensation value of 2.2
6) Range set for Salinity
7) Calibrated Probe Dry = 000
8) Calibrated Probe High 53000 = stabilized around 480 (but has varied a bit up to as 525 to as much as 607)
9) When completed it reads ~35 ppt on the screen while in the Calibration Fluid but drops to as low as 18-22 when placed in the sump water which was previously checked to be accurate on the Refractometer.

Kinda boggles me too. I may be doing something totally stupid. Maybe I should just use the tank water as the calibration fluid instead since it supposedly is already at 35 PPT/ 1.026 salinity already.

Oh well just updated to the latest Firmware and everything seems to work better.