View Full Version : Frustrated with my AC III!!!

08/16/2008, 04:36 PM
Hey guys, wondering if I can get some help/ direction on setting up my AC III.

I setup my tank and all my testing using kits shows me spot on for parameters - pH, ORP and Temperature.
I tried calibrating the various probes when I put them in and am receiving wildly off the mark readings.
My tank pH is indicated at 7.8 after calibration. If I reset, it goes to 8.5.
Testing claims my pH is 8.2.

As for ORP, I can neither confirm or deny what it is since that's my only measurement. However, I adjusted the offset using Aquanotes once I had the probe in ORP 400 solution but now it reads a very low number in the tank which is unlikely - 265!

Are my probes bad?
Did I screw something up with my AC III?
Will Spiderman reach Mary-Jane in time?

These are all things I need answers to so I hope you can help and thanks in advance! :)

08/16/2008, 04:58 PM
I am not looking at the instruction book at this time, but I seem to remember when you calibrate the probes you also have to have the temperature probe in the solution also to account for the temp? Double check the instructions and see what they say.

08/16/2008, 07:02 PM
I can't answer all the questions but I can answer one:
yes, spider man will reach mary jane in time. :D

08/16/2008, 08:20 PM
Hehe... that's one question down, two to go! :)

08/16/2008, 10:28 PM
There is a break in period with ORP probes. Typically a new probe reads low and go up by 20 to 50 mV per day until it stabilizes. The break-in period may take as long as one week.
Confirm the calibration of the pH probe by going to the run display, and checking that 7 reads 7.0 and 10.0 reads 10. If so, I believe the pH probe reading. Most color matching test kits are inaccurate, and typically read high.


08/18/2008, 05:02 PM
The only pH solution I have is 4.0 and I tested that... but it looks like I am about -0.48 off.

After testing with 10.0 solution things look much better - my True pH is actually 7.9.
Thanks for the help!