https://www.amazon.com/Litmus-Strips-Universal-Application-Packs/dp/B00S730YWG/ref=sr_1_3?crid=1NJY2DWG77J67&keywords=ph+test+strips&qid=1552700682&s=gateway&sprefix=pH+test+%2Caps%2C201&sr=8-3
this has a wide range of pH indication.