I know many members have this unit. Is it just a slow thinker when calculating PH or do I need to switch out batteries. Temp. shows immediately but PH reading is painstakingly slow and once it gets to a reading stops and then may move a tenth of a fraction either way before settling down. It's like waiting for my dog to find the just right--that perfect plot of land to do her thing--come on now its all grass. Any tricks of the trade? Of course, it is slower with added supplements etc.