Damn you are full of useless information Aaron. If you have no idea about what you are talking about DONT SAY ANYTHING.. Bad information is worse than no information!
Depending on the make and model controller/monitor, you will need different ph solutions to calibrate it. For the Milwaukee controller you need 4 and 7 "not 4 and 10". 7 is used as the set point (offset) and the 4 is used for the slope.
For American Marine units the calibration fluids needed are 7 and 10 only.
How to Calibrate and Use a pH Meter The most important aspect of using a pH meter is correctly calibrating it. Each meter will have a slightly different method of calibration. A number of general rules are very useful, however: 1. Any analytical method, including pH measurement, is best calibrated with quality standards that span the range expected to be measured. Most aquarists calibrate pH meters using two solutions of known pH. A meter that allows only one calibration point is a very poor choice. Using more is fine if the meter allows more than two. When using two solutions to calibrate a pH electrode for use in a marine aquarium, one calibration point should optimally be below 8.0 (typically 7) and one should be above 8.5 (typically 10, but 9 is also sometimes used). When measuring pH in something other than aquarium water, there may be special tricks to use which are detailed below.
Using pH 4 and 7 is often done, but can be a less optimal choice because the range expected to be measured for reef aquarium water (about pH 7.8 - 8.6) is outside of this calibration range. In some cases the error is small enough that this is acceptable; while in others, it may be a problem.
Additionally, when measuring pH in a fluid of a lower pH (such as inside a CaCO[SIZE=-1]3[/SIZE]/CO[SIZE=-1]2[/SIZE] reactor), calibrating at pH 4 and 7 is more sensible than calibrating at pH 7 and 10.
Once again Aaron, As I have tried to be nice about this in other threads. You are trying to be a wise ass and I am getting tired of it. You give 2nd and 3rd hand knowledge about everything without any facts or evidence that it works. Learn to listen and educate yourself about these things before posting.
You can copy and paste from any where you like. When someone asks for help they arent looking for maybe or I thinks !!
"It is better to be thought of as a fool then to open your mouth and remove all doubt" Wise words to live by Aaron.
The next time I see you interact with members in a nasty way (ie: calling people out of thier names or calling them fools) Now you have been warned.