PH pens off of e-bay good or bad?

PH pens off of e-bay good or bad?

it all depends on the seller. i just bought a PH wand like a truncheon for $50usd. check the feedback, if they have 100%-99.6% (positive feedback) then they should be good.

The brand is very important and as always: you get what you pay for. Depending on the money available, I would recommend an Oakton tester. They will run $40-90 but are well-worth the cost.