I've always used pH test kit. Have to pH my pool and stuff too so I'm pretty accurate, never needed a pH wand. Well, need to move on to week two of flowering on Wednesday so I guess I'll just drain the reservoir and start her fresh from week two. Just tested again. . . seems to have moved up to about 6.0. I like it at 6.5 just 'cause I like that yellow/green color in the beaker but guess yellow will have to do for a couple nights.