Havent bought one in years. Owned like 6-7 of them in the past. So i bought from a hydro store soaked it in water and then ph and 7 worked just fine . Now the 4 ph at 7. So i cant get it to read 4. Say 4 or even calibrate at 4. So i took it back. He gave me another one. Same exact thing. I went and bought 4 and 7 again solutiion Tryed and same thing. The 4 calibrated at 7. And the 7 calibrates at 7. Has this happened to anyone else
