Can anyone recommend a good, accurate TDS meter. I am tired of playing guessing games with the cheap garbage that Amazon sells. I had 3, all on the same scale, all give very different readings and ALL got smashed with a hammer this morning while mixing my nutes. They all do the same thing, test your liquid, pull it out, wait a second then put it back in and have a 200 ppm difference, keep doing that and never get even close to the same number twice. I had enough of guessing games so I got the hammer out and got rid of the problem's. Thanks in advance for any help.