# Question about readings **URL:** \ **Category:** Nutrients\ **Created:** [January 22, 2021, 4:55pm UTC](https://ilgmforum.com/t/question-about-readings/61643 "2021-01-22T16:55:08Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![pedally](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/pedally/32/403000_2.png) [@pedally](https://ilgmforum.com/u/pedally)\ **Post date:** [January 22, 2021, 4:55pm UTC](https://ilgmforum.com/t/question-about-readings/61643/1 "2021-01-22T16:55:08Z")
I have been using a Vivosun TDS & EC (hold) meter and I’m not sure how to read it. Before watering with straight purified water my EC was 27 and my PPM was 6. Taking a sample of the runoff my EC was 345 and my PPM was 175. Checking the FF watering guide, they recommend an EC of 1.70-1.90 and a PPM off 1190-1330. (Just an example of how they have it for week 5). I have no idea how to convert my readings to their readings. Do I have a faulty meter or am I missing a step or two? Thanks ---
**Author:** ![BobbyDigital](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/bobbydigital/32/1220557_2.png) [@BobbyDigital](https://ilgmforum.com/u/BobbyDigital)\ **Post date:** [January 22, 2021, 5:12pm UTC](https://ilgmforum.com/t/question-about-readings/61643/2 "2021-01-22T17:12:05Z")
Your meter reads in micro Siemens and you’re looking for milli Siemens. You need to move the decimal place 3 places to the left on your ec. So if you’re a reading of 345, it’s actually .345 ec ---
**Author:** ![Myfriendis410](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/myfriendis410/32/556067_2.png) [@Myfriendis410](https://ilgmforum.com/u/Myfriendis410)\ **Post date:** [January 22, 2021, 6:27pm UTC](https://ilgmforum.com/t/question-about-readings/61643/3 "2021-01-22T18:27:49Z")
500 ppm NACL scale equals 1 EC. Like @BobbyDigital said; you need to move decimal to the left.