pH buffers are very simple to make, and are surprisingly expensive to buy. For that reason, I thought DIY pH buffers would be a good article in the future. Easy to make, last a good while in a cheap closed soda bottle, and one can easily make a lot at once.
What I don't know is what pH values people really need these days. Obviously we want to bracket the pH in reef tank, with something like 7 and 10.
Many pH meters allow you to use most any pH values you want to calibrate, and can use more than 2 buffers.
But the simpler devices are usually only 2 (just one is a bad idea), and often they are fixed.
So what fixed values do people need?
One reason I'm asking is that a surprisingly large numbers of inexpensive buffer packet sets are 4, 7, and 9.18. I've never personally used a meter that needed pH 9.18, but they may exist.
Are there common reefing pH meters that need pH 9.18 for calibration? If so, its easy to make. if not, I won't bother since some do require pH 10.
TIA.
