Orp?????

[jla72262]

Ok, guys, I have my Apex up and running..... I went all out and got all the probes, I have and ORP reading of 294 at present, unfortunately I have NO clue what the ORP means, I just know that the readings aren't whats important, it's the changes in the readings during certain times, right or wrong? I have seen others reading way higher than 300 so just want to be sure I don't have any problems. Thanks!:facepalm:

[jla72262]

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[JMurphy97]

I think it's for if you are dosing ozone or something. I have a reef keeper with a orp port on it but I don't use it. It came on the module that includes the ph, which I use.

[Heliman]

As an absolute parameter, ORP does not have a lot of significance. As a trend indicator it can be useful.

If, over a week or so, your ORP reading is trending down, then you have a problem , possibly with accumulating debris (reducing compounds), if, on the other hand, your ORP is on a rising trend, then your system is more oxydative (healthy).

If you are dosing Ozone, then ORP redings are a vital measure of whether free Ozone is getting into your system (very high ORP, over 400)

My ORP, on a healthy, stable system (without Ozone) runs at 370 overnight, falling to about 340 during the day. This set of readings has been steady for a long time.