View Full Version : ORP probe for Apex

11/29/2012, 10:49 AM
I just came over to the dark side and got an Apex and am wondering if pH and ORP are that important to constantly monitor, especially ORP. I'm pretty sure I know enough about ORP to know I don't know enough about it to use ORP readings to help my tank inhabitants.

My Apex didn't come with an ORP probe yet pH, ORP, temp, and current seem to be the featured tracked parameters on the display, the web app and my iPhone app. So I'm interested in finding out how many of you invested in an ORP probe and why and what should or can be done about low, high or falling/rising readings.

This isn't a trick question, I'm really curious why ORP seems to be a somewhat featured parameter on all the displays the Apex uses.

11/29/2012, 11:13 AM
ORP is a great indicator of water quality. Once your probe stabilizes and you start to get a daily reading, you will quickly note when/if water quality drops. You won't know WHY it dropped, just that it did. Could be just regular maintenance and you stirred up the sand. Could be something died. Point is, something happened and the ORP probe lets you know about it.

And you must have meant that you came 'from' the dark side, not 'to' the dark side! :)

11/30/2012, 09:39 AM
OK, I see your point, a probe to see a trend is only about $50 so it's not unreasonable "insurance." Why does coming here always cost me $$$ ? :-)

One quick question ... when you say, "Once your probe stabilizes ..." about how long should that take? I was under the impression ORP fluctuated throughout the day similarly to pH although inversely and not to expect an equilibrium state.

11/30/2012, 09:43 AM
An ORP probe takes a while to register properly once placed in your tank. They're not like a pH probe. Don't ask me to explain why because I don't know!

It takes about 1 week for them to stabilize. During that time your ORP reading will steadily increase to wherever it will finally wind up at. Once it starts rising/falling inverse to pH, then it's ready to use. As long as the values are just steadily going up every day, then it's not ready.

11/30/2012, 12:47 PM
Thanks for letting me the ORP probe would just keep sending ever rising values for that long. I probably would freaked out and tried to do something to stop it from going higher. Just what I would have done ... I have no idea.

11/30/2012, 02:21 PM
Ya gotta give it a good soak!

12/15/2012, 07:28 AM
Ya gotta give it a good soak!

The probe was installed three days ago and the readings are still rising. Started out at around 205 and is now 310. It fluctuates a little depending on the time of day but the overall graph line is an upward slope.

It's a pinpoint ORP probe and it came with a foil pouch of 4.00 calibration fluid. I followed the Apex calibration screen instructions ... don't ask me why I bothered since I have no idea what the absolute ideal ORP reading should be or what to do about controlling it.

12/15/2012, 07:39 AM
You can't calibrate it with just a packet of 4.00 pH fluid. It takes Quinhydrone along with pH 4.00 and 7.00. Best bet with ORP probes is just leave them alone when you get them.

As long as your ORP value continues to rise, then it's still breaking in. Only when it starts to rise/fall opposite pH can you consider it ready.

It's possible you've messed up the probe readings. What I'd do at this point is leave it alone and let it stabilize first. Since there's no 'right' number for ORP, it might not matter all that much. Let's see what it settles at and how it behaves over the course of a day. You can always get a packet of the 400ms calibration fluid that's used for other probes and just see if you get a reading of 400 when you set the probe in it. Don't try to calibrate to 400 though, you can't do it. If you're way off, then there's a way to manually enter a slope and offset and get the probe back to 'factory' settings if you will.