Neptune Controller Question

[Grayout]

Question for all of you reefers that are using Neptune controllers.

I've searched through the Neptune owner's manual several times and just can't seem to find my answer. Hopefully, someone here can answer my question.

I'm currently using a AquaController II and have a question regarding setting ORP and PH.

Within the Setup section of the controller one is able to calibrate ORP and PH. Also, within that section the controller asks whether or not you wish to calibrate for temp (PH) and PH (ORP). The choices given are either yes or no. What should I select?

I've noticed that if yes or no is selected, the readings for PH and ORP are dramatically different.

Thanks in advance.

[BobB]

In your fourth paragraph, I believe that's "compensate" not calibrate. pH and ORP are temperature-dependent and will vary with temp. With the compensate turned on, the pH and ORP readings is adjusted automatically based on the temperature of the water. On my AC Pro, I have the temp-compensation on and it seems to accurately reflect the pH and ORP. I hope this helps,

Bob

[Grayout]

Yes, you are correct. My apologizes for the confusion.

Thanks for the info. It's been throwing me off for some time. I guess I will turn on both to compensate for the temp swings.

[Grayout]

I just read this in the Neptune System's section of the site. I think I'll go with the off setting for both. The ORP reading is much higher with the compensation on.

"There is a small variance in the pH reading depending on the temperature of the water. Turning compensation on corrects for this variance. In a typical reef tank the temperature change is so small that the effect is negligible. For reef tanks I recommend just leaving it off.
pH and ORP are inversely correlated. For every one unit change in pH there is about a 58 mV change in ORP. Turning pH compensation on corrects for this variation. However, the industry norm is for compensation to be off. So if you want to compare your ORP readings to books, and others leave it off. I recommend leave this setting off as well.'

Curt

[Aquaduck]

I was told by Curt of Neptune Systems that temperature compensation is only required if you are keeping coldwater species. At normal aquarium temperatures (80) compensation is not required.

[impur]

I think it also comes in handy if you use a seperate thermometer in the tank. Typically, especially with digital thermometers, the reading can be slightly off. If you are used to adjusting your tank according to that thermometer, you can compensate the amount the thermometer is off on your controller.