You've got your Apex mounted, connected to your network, and you've updated your Apex AOS (DO NOT proceed any further in the setup process if you have not yet updated your AOS), so now you're ready to get your probes connected and calibrated.

In this article, we will guide you in connecting and calibrating your pH probe. If you would like to read a thorough explanation of pH and its impact on your aquarium, check out this article by Randy Holmes-Farley.

Connecting Your pH Probe to Your Apex

Begin by identifying your pH probe and the port it will connect to.

Also, please remember that all of your probes are fragile and should be handled with care.

Your pH probe is the blue probe that came included with your Apex.

Note that your pH probe will connect to upper BNC connector near the center of your base unit right between the temperature probe port and the ethernet port.

Now, connect your pH probe to your Apex base unit as shown in the video below.

Now that your pH probe is connected to your Apex, you can proceed with calibrating it.

Calibrating Your pH Probe

To begin calibration, you will need to log in to your Apex. You can do this operation from either your Apex Local Dashboard or Apex Fusion (our article for connecting your Apex to Fusion can be found here).

This article will demonstrate this operation as performed from Apex Fusion.

First, log in to your Apex Fusion account.

Then, from your Apex dashboard, click the configuration button.

This expands your Apex controls.

Next, click the inputs button.

This will take you to your inputs configuration page. On this page, select pH as shown in the image below. This will take you to the pH probe configuration page.

Once on the pH configuration page, click the Automatic Probe Calibration button.

You are now beginning the calibration process. Click "Calibrate" to continue.

You will calibrate the low range of your pH probe first. To do this, you will need the low range 7.0 calibration fluid that came with your Apex.

Your probe should have a cap on the end filled with a solution designed to keep it wet until installed. To continue with the calibration process, remove that cap, and then place your pH probe in the 7.0 calibration fluid.

Now, click the "Next" button in Apex Fusion.

Your Apex will begin to automatically calibrate your pH probe.

You should see indicators showing that the probe is 1) reading in the acceptable range, 2) settling in on a reading, and 3) counting down toward completion. (While you will see a timer, your probe may may complete calibration before the countdown is finished.)

If you notice that your probe seems to be having difficulty reading in the acceptable range (as indicated by a red caution triangle), gently shake the probe in the solution.

When your low range calibration is completed, you should see all 3 check marks as in the image below.

Now, click "Next" in Fusion to continue to high range 10.0 calibration.

For this part of the process, you will need the 10.0 calibration solution that came with your Apex.

Before continuing, rinse your pH probe in RODI water to remove the low range 7.0 calibration solution.

Then, place your probe in the 10.0 calibration solution.

Now, click "Next" in Apex Fusion to begin calibration. Once again, you will see that the probe is calibrating with the indicators of acceptable range, settling of the reading, and time remaining for calibration.

When the process has completed, you will again see all 3 check marks indicating your pH probe has completed high range calibration.

Click "Next" to see the verification that you have completed the calibration process.

Now, place your pH probe in your sump. Your probe should ideally be placed in a probe holder of some sort designed to hold it in place.

Make sure that your probe end is completely submerged in the water, but ensure that the wire end is above the water's surface. When using a probe holder, be careful not to over tighten the screw holding your probe in place as you may damage the probe.

You will now see readings of your pH probe in Apex fusion.

If you would like to adjust the preset minimum and maximum value range of your pH probe (these control when you will receive alerts from your Apex about your pH levels), click on the gear icon located above your pH readings. This will take you to the pH configuration page.

Congratulations! You've successfully connected and calibrated your pH probe! Next we will continue with the installation and calibration of your salinity probe.