ORP

[Hardridge]

My ORP stays around 400 to 410. I use ozone. As soon as I do about 15% water change it drops below 300 is this normal or is it Somethg wrong with water. I am using a new RO/DI system.

 

[ccCapt]

That's normal.

 

[carey]

On this subject....lol...I am planning on getting a controller that can monitor ORP and was wondering if it's even worth the cost of the probe . Is it a good measure of something or just "fluff"

 

[ccCapt]

If your not injecting ozone you have no need to monitor ORP.

 

[Hardridge]

Thk u I didn't know it would drop that low. Could u explain to me why just interested in learning more

 

[ccCapt]

ORP is very complicated, but to explain the reason for the drop is basically that a new mix of fresh saltwater usually has an OPR of about 200-210 mV. You are adding that to water that reads 400 mV so a drop in mV is to be expected.

If you want to do some reading up on Ozone and ORP, here are some good articles.
ORP and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com
Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry by Randy Holmes-Farley - Reefkeeping.com
Ozone and the Reef Aquarium, Part 2: Equipment and Safety by Randy Holmes-Farley - Reefkeeping.com
Ozone and the Reef Aquarium, Part 3: Changes in a Reef Aquarium upon Initiating Ozone by Randy Holmes-Farley - Reefkeeping.com