PH Tester Help

You'll need 3 things. 1) PH 4.01 and PH 7.01 calibration solution 2) *Storage solution/ Buffer 4.01 solution (to keep the diode hydrated) 3) General purpose clean solution. every month calibrate your tester with both solutions (4.01/7.01) and clean the diode with distilled water between the solutions, you should use as first the 4.01 one, then clean it with destilled water and then adjust it with the 7.01. Every time you are going to storage it a good practice is to clean the diode with distilled water, then, you need to use ph 4.01 or a storage solution in the cap (the enough amount to have the end of the cap with a thin layer) to keep it hydrated till the next use. Every 2-3 months use a general purpose cleanup solution to keep the surface of the diode clean, it will help to have a quicker response and keep it in good condition for a long period. *You can avoid the storage solution if you buy a big bottle of 4.01 solution to keep it hydrated.