How do I check the Vivosun TDS & EC Pen for accuracy

Fred4

Member
Hi, I just purchased the Vivosun tds ec pen from amazon . It is my first meter so not familiar with the readings. Today I checked my runoff and the ppms showed 627 and ec showed 1255, cant see how the ppms could be that low and I dont know what ec is but the number is twice the ppms. Was hoping someone could tell me a way of verifying the accuracy of the pen. Thanks
 

rundlescunder

Well-Known Member
Hi, I just purchased the Vivosun tds ec pen from amazon . It is my first meter so not familiar with the readings. Today I checked my runoff and the ppms showed 627 and ec showed 1255, cant see how the ppms could be that low and I dont know what ec is but the number is twice the ppms. Was hoping someone could tell me a way of verifying the accuracy of the pen. Thanks
I had that same pen. It was broken. Dude at the hydro store told me those were generally one and done but some people try and keep them. But vivosun with a lower case v is trash.

edit my b I read it as ph im pretty stoned. I had a vivosun ph pen. Still vivosun stole dollars from me when i was first buying stuff. They are garbage
 

Jjgrow420

Well-Known Member
buy a bluelab or hanna then check ph/ec of the water, check with vivosun meter then throw out vivosun meter because its crap and you now have a big boy pen
ec is measured in single digit values
eg. 1.0 so you cant have an ec of over 1000 or else youd be looking at rock salt
there are 2 ppm scales. x500 and x700
you were likely switching between the 2 scales and not reading the ec reading
you need to do some research into understanding ec levels and reading ppm anf converting to ec. its not as simple as getting a cheap meter to get a reading.
 
Last edited:

Fred4

Member
buy a bluelab or hanna then check ph/ec of the water, check with vivosun meter then throw out vivosun meter because its crap and you now have a big boy pen
ec is measured in single digit values
eg. 1.0 so you cant have an ec of over 1000 or else youd be looking at rock salt
there are 2 ppm scales. x500 and x700
you were likely switching between the 2 scales and not reading the ec reading
you need to do some research into understanding ec levels and reading ppm anf converting to ec. its not as simple as getting a cheap meter to get a reading.
I just took a reading again with the leftover runoff and it read ppms 604 and ec 1209, I took a couple pics to post , guess I got a dud lol
 

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Jjgrow420

Well-Known Member
can you change the unit of measurement?
your ec is 1.2
generally you can get away with a cheaper tds meter but personally i wouldnt risk it. can you get a buffer solution? then you can test the meter and make sure its reading right.
 

Jjgrow420

Well-Known Member
Conductivity is usually measured in microSiemens (µS/cm) Another unit of measurement for EC is mS/cm or milliSiemens per centimeter. 1 mS/cm = 1000 µS/cm and you will often find measurements displayed as mS/cm for higher levels of EC (i.e. 2000 µS/cm or more).
you can use either measurement but the more common ec measurement is ms/cm. see if you can change the mode on the pen
 
how to read microSiemens (µS/cm) and convert it to ec? multiple value x100. example. 25x100=2500/2=1250ppm if some looking EC values, list below.

250 PPM = 0.35 EC
600 PPM = 0.85 EC
800 PPM = 1.14 EC
1000 PPM = 1.42 EC
1200 PPM = 1.71 EC
1300 PPM = 1.85 EC
1400 PPM = 2.00 EC
1500 PPM = 2.14 EC
1600 PPM = 2.28 EC

i hope this help someone to find fast info =)
 

DougF

New Member
buy a bluelab or hanna then check ph/ec of the water, check with vivosun meter then throw out vivosun meter because its crap and you now have a big boy pen
ec is measured in single digit values
eg. 1.0 so you cant have an ec of over 1000 or else youd be looking at rock salt
there are 2 ppm scales. x500 and x700
you were likely switching between the 2 scales and not reading the ec reading
you need to do some research into understanding ec levels and reading ppm anf converting to ec. its not as simple as getting a cheap meter to get a reading.
Discovered my VivoSun EC meter was lying. Read ok in the double digits, but after that, way low like 90%. Went with Blue Lab, and what it tells me seems more plausible. Have not determined accuracy of my Vivo PH pen.
 

Star Dog

Well-Known Member
If you're going to stick with it buy a blue lab when you're flush.
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Then again if it's accurate it's accurate you'd need to test it?
 
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