Apex Classic - ORP Reading High After pH Probe Install

a6walter1 · Dec 4, 2017

As you can see on the above graph, the ORP is the orange/goldish graph, while the pH is the reddish orange graph. I had the ORP connected to the Apex base unit for a while before my pH probe came in the mail and it was reading a reasonable number (300ish). As you can see, last night at 10pm or so I installed/calibrated my new pH probe, and immediately the ORP was reading incredibly high.

Thoughts??

n2585722 · Dec 4, 2017

Probes can interfere with each other. How close are they to each other?

a6walter1 · Dec 4, 2017

I have this probe holder, and they are in the right and left holes.

http://www.eshopps.com/products/accessories/19250/

n2585722 · Dec 4, 2017

That is close. To make sure it is probe to probe interference put some tank water in a cup and place one probe in the cup to isolate them. If both read correctly then the next thing would be to try and put more distance between the probes. If you still have an issue I would contact Neptune Systems. There may be an issue with one of the probes are the module they are connected too. They may have other test for you to try to try and isolate what is causing the interference.

a6walter1 · Dec 4, 2017

Okay, cool. I will give that a shot tonight and report back. Thanks!!

a6walter1 · Dec 4, 2017

Well, I took the orp probe out and put it in a cup of tank water. The reading immediately fell, but continued to fall well below 100, so I'm almost thinking it is something wrong with the probe itself.

a6walter1 · Dec 4, 2017

Well I took the orp probe out and put it in a cup of tank water. The reading immediately began to drop, but it kept dropping to well below 100. So I'm thinking the probe may be bad and maybe it was a coincidence that it started behaving strangely when I plugged in the pH probe.