Apex PH probe calibration start to end

Tangdora

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Hi all

Wanted to write up a short post walking through my start to finish experience on calibrating the Apex pH probes. Currently on my set up. I have two, one for the tank itself and one for my calc. This is only the second time I have calibrated, first being the initial set up which was done through the automatic process. However , this time around, I put a lot more thought into the process and was achieve extremely close accuracy of .02 or less variance from the calibration solutions. I will note before I dive into it, it took me two attempt, making a few tweaks along way based on recommendations from other post already out there. Also since day 1 my second ph prob has always been off by .25-.3 point since it’s initial calibration which I have alway attested was just due to a bad probe given that it arrived with no liquid in the cap. My first of two attempts in my most recent calibration resulted in roughly the same variance, However wasn’t quite ready to call it below are the steps I took to getting both back under .02 variance

Part 1 Cleaning

Won’t take any credit for this. I typically deep clean the components of my tank every 6 month so now for the probs I have decided to follow @SuncrestReef #23 post for cleaning


Part 2 Calibration

1) Upon completion of the cleaning step soaked the probs back in the sump for 30 mins. This is mainly just so that at the same time you can soak your calibration solutions in the tank as well to ensure solution temperatures match the tank temp. In my case I went with the Hanna 4,7 and 10. The 4 & 7 for reactor probe and 7 & 10.

(1st key to note I personally decide to just pay the extra 2 bucks that my local LFS sells these calibration solutions for not cross contaminate pH 7 solutions. Used one for each probe)

2) Not sure if my personal solution below led to the low variance post calibration or if it was this but I decided to take @JDubb_4051 suggestion, and run the manual calibration using Apex.local as opposed to the fusion app


3) remove the probe from the sump or tank and dip into RODI then dry it completely off with a paper towel. Then used an air duster to blow any water that was on the glass

4) This is the part that I believe led to better calibration readings. Only only remove low solution from tang water leave the high solution in the water still do not allow temperature to start dropping. Before entering into the manual calibration mode, I put the probe into the lower end solution first gave it a few shakes to get the bubbles out and allowed it to settle before starting the calibration. The procedure itself, doesn’t stay at the beginning don’t to have the probe out first. I left it settling for about two minutes before confirming a stable PH reading before entering the calibration. Once the low end calibration started, I did not shake or move the probe and only allowed the confidence to hit 100% before proceeding this. I believe by allowing it to properly settle outside the calibration the proper offset and adjustment are then applied once stated When it sees how off it really is low end solution

5) remove the probe from first solution repeat step 3

6) take the high solution from the tank water and please probe in it. Shake and twist probe prior to starting step two. Then proceeded to the confidence meter. Twist the probe gently back-and-forth until you achieve 100% and that the value stays the same for 15 seconds after

7) Hit next to complete process then repeat step 3 and place probe back into the solution. Hopefully you’re variances is quite minimal and at least below the Apex recommendation of .065 afterwards, repeat step 3 one last time, please probe into the high solution and check your variance once more


Hope this helps people new to the Apex system like myself in any others
 

kindafun

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Very nice write up, thank you for sharing. I’ll give it a try next time.
 

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