I use pH papers for this. They come at different pH ranges (different sensitivites to certain pH ranges) and change color based on the pH of your solvent. The packages always have the calibrated color scale so within a minute you know the pH fairly accurately.

Hey

The best way if you are not going to use the ph meter, use the ph papers. you just need to dip it in the solution before and after changing the ph. and then by matching the color change you can have the idea about the ph. it wont be exact as the ph meter but its good and reliable,

Best

Shoaib,

pH meter for Reynolds stain is an overkill. Litmus paper can be used but (as I see it) is not mandatory. Stain prepared according to protocol works fine even without pH adjustment.

Here is standard and simple protocol:

http://oharalab.ucsf.edu/common/Techniques/Reynolds%20lead%20citrate.pdf

For measuring the pH scale we can use pH-meter or chemical indicator ph.ph and Litmius paper so that you have option to seleced the method .but take care the use pH-meter must calibrated before measureing the sample using buffer solution PH=10.

Use pH paper, if you are not going to use pH meter.