View Full Version : PH and ORP

03/24/2007, 07:39 AM
My PH is 7.4 and my ORP is 180, how do I raise them?

03/24/2007, 10:22 AM
Well lets start with equiment. What brand pH test kit and how are you measuring ORP ?

03/24/2007, 10:30 AM
the test kit is the Saltwater master test kit from aquarium pharmaceuticals(It actually shows 8.2. The readings I am talking about the 7.4 and the 180 are coming from my aquacontroller III. I calibrated the PH probe per the instructions.

03/24/2007, 10:36 AM
Well first, the AP ph kits are very reliable in my experience so I would say there is something wrong with your controller. I would contact the manufacturer for advice. I really doubt your pH is 7.4

It is possible to have an ORP of 180 mv but I suspect that is off too.

Try putting your ORP probe in a glass of white vinegar and see if you get around 450 - 525 or so.

03/24/2007, 11:03 AM
will do

03/24/2007, 11:34 AM
What is ORP?

03/24/2007, 11:47 AM
Oxidation Redox Potential.

It measures the redox potiential of the water and is expressed in millivolts.

Organic material in aquariums decay and require oxygen to process. The more decay, the more oxygen is used. Water with a higher level of ORP is suppose to be able to deal with this process better.

Most people that run ozone use ORP monitors and controllers to control the amount of ozone being dispensed.

03/24/2007, 01:12 PM
I don't believe the pH measurement either. I wouldn't try to control ORP. It's a very complicated function of the setup. This article might help:


03/24/2007, 08:46 PM
If your AC3 ORP probe is new, it takes a week or so to stabilize. I had similar readings when I first put the probe in an sps tank, about a week later it's ~300... I did confirm this with Neptune Systems.