Henry on Nostr: Do you have a meter that can measure EH that you might recommend? I know they are ...

Do you have a meter that can measure EH that you might recommend? I know they are effectively useless for soil but there are some water based things I wouldn't mind getting a grasp on what is going on with on that side of things. E.g some of these sprays and the biodynamic 501 prep with the quartz.