Hello, hope there is someone here that knows ORP and ORP probes and can give me some good advice or answers 
I have set up a new tank about 4 months ago, and installed the Apex system including a lab grade ORP probe.
Since I have never measured ORP before and had no experience, I have not been watching it very closely, but after some reading i found out that a good place to set the HH alarm was around 450.
During the following months, the ORP has been going up and down a bit, but has never triggered the HH (or LL) alarms before. (not even been very close really)
So... to the problem. On monday 28 december, i got an email alarm that ORP had reached my 450 limit. I was away on my cabin at the time (Off course stuff like this happens at a bad time), so all i did at the time was to follow the graphs on Fuision.
The next morning, ORP was still steadily climbing, and was now at 470. I called my sister to get her to check the tank, and everythink looked normal. In the evening it reached 499, so I turned off the skimmer to see if that helped. The ORP stopped rising, and even had dropped down a bit to the next morning. (to 480 at the lowest)
I came home in the afternoon on the 31st, and everything looked like normal in the tank, so i turned the skimmer back on, and immediately the ORP started climbing again.
The next day i did a small waterchange (50 liters out of 850 liters in my system) - no change in ORP reading.
I took the probe out and cleaned it with a toothbrush - no change in ORP reading.
I put the ORP probe in a cup of fresh water - no change in ORP reading.
I put a good dash of 35% vinegar in the cup of FW and left it there for about 30 minutes - no change in ORP reading.
Cleaned the probe with a toothbrush, flushed it in freshwater and put it back in tank - no change in ORP reading.
Did another waterchange of 100 liters - no change in ORP reading.
Since then i have just ignored my ORP, since i dont have a clue what is going on or why?
The ORP has continued to rise and looks like it has stabilized at around 530 now.
Does anyone have a idea what is going on, and why? Has my probe gone mad or is there something going on in my tank that causes this high ORP?
(what causes hight ORP other that skimmer, airstone or ozone? (I dont have an airstone or run ozone)
I have set up a new tank about 4 months ago, and installed the Apex system including a lab grade ORP probe.
Since I have never measured ORP before and had no experience, I have not been watching it very closely, but after some reading i found out that a good place to set the HH alarm was around 450.
During the following months, the ORP has been going up and down a bit, but has never triggered the HH (or LL) alarms before. (not even been very close really)
So... to the problem. On monday 28 december, i got an email alarm that ORP had reached my 450 limit. I was away on my cabin at the time (Off course stuff like this happens at a bad time), so all i did at the time was to follow the graphs on Fuision.
The next morning, ORP was still steadily climbing, and was now at 470. I called my sister to get her to check the tank, and everythink looked normal. In the evening it reached 499, so I turned off the skimmer to see if that helped. The ORP stopped rising, and even had dropped down a bit to the next morning. (to 480 at the lowest)
I came home in the afternoon on the 31st, and everything looked like normal in the tank, so i turned the skimmer back on, and immediately the ORP started climbing again.
The next day i did a small waterchange (50 liters out of 850 liters in my system) - no change in ORP reading.
I took the probe out and cleaned it with a toothbrush - no change in ORP reading.
I put the ORP probe in a cup of fresh water - no change in ORP reading.
I put a good dash of 35% vinegar in the cup of FW and left it there for about 30 minutes - no change in ORP reading.
Cleaned the probe with a toothbrush, flushed it in freshwater and put it back in tank - no change in ORP reading.
Did another waterchange of 100 liters - no change in ORP reading.
Since then i have just ignored my ORP, since i dont have a clue what is going on or why?
The ORP has continued to rise and looks like it has stabilized at around 530 now.
Does anyone have a idea what is going on, and why? Has my probe gone mad or is there something going on in my tank that causes this high ORP?
(what causes hight ORP other that skimmer, airstone or ozone? (I dont have an airstone or run ozone)
