Do you test using EC or PPM?

[theroadwarrior]

I have heard that using EC to measure nutrient levels is more accurate than the more commonly used PPM. Curious as to what people use for their grows. I am looking at getting a pen but interested to know if a EC pen will give me a more accurate reading.

 

[Slap]

I use both just as kind of like an insurance policy, I like to be as safe as possible and it never hurts to double check.

 

[dongle69]

One is no more accurate than the other.
People should communicate in terms of EC, though.
When someone says 500ppm, that causes confusion because of the different ppm conversion factors.
So you would have to say 500ppm at .7 conversion or whatever.
When someone says 2.0 EC, it means exactly that.

 

[Mickymouse]

Mines got both one on each side of the lights hands down this one is the best ask around.Asking what one is more accurate is like asking what is more accurate farinhite or celceus for tempature.

http://www.4hydroponics.com/grow_room/truncheon.asp

 

[Che]

EC is more reliable, for the reasons Dongle69 mentioned above. If you can, choose the EC meter, however its not always possible to get one, depending on which retailers you choose to shop with.

If you do buy a PPM meter, just make sure you know the conversion rate so that you can use the appropriate calculations to properly adjust nutrient content levels.

 

[theroadwarrior]

One is no more accurate than the other.
People should communicate in terms of EC, though.
When someone says 500ppm, that causes confusion because of the different ppm conversion factors.
So you would have to say 500ppm at .7 conversion or whatever.
When someone says 2.0 EC, it means exactly that.

Thank you very muchFinally I understand.

 

[theroadwarrior]

Mines got both one on each side of the lights hands down this one is the best ask around.Asking what one is more accurate is like asking what is more accurate farinhite or celceus for tempature.

http://www.4hydroponics.com/grow_room/truncheon.asp

Thanks I was considering that one or another at eco. Yes after dongle's explanation I understand now

This site has really benefited me so thanks all for your replies.

 

[FreezerBoy]

To take it one step further, no one measures ppm. Everyone measures EC and EC only. The problem is that many testers hide EC and exchange it with nonsense. There are at least six different bullshit factors used which is where the confusion stems from. As Dongle said, EC is EC and that's it.

Note your plants are illiterate. They don't care. As long as you can track your numbers you can run your garden.

 

[pontiac]

protip- almost all US manufacturers (hanna, HM digital, sunleaves, oakton, etc) use the .5 conversion factor by default.

 

[dongle69]

This being an international site, it is important to make no assumptions of conversion factor.
Many of Hanna's products for instance ship with a .7 conversion factor.

 

[FreezerBoy]

They also do .640 and .650.

Are we confused yet?

 

[dongle69]

Not if we use EC!

 

[Greyskull]

does EC = TDS?

that shit confuses the hell out of me....

 

[samba]

EC here...

 

[BobbleheadJed]

I didn't have a problem with testing in ppms until I started talking about it with other people. Then I learned. But I'm not going to spend more for a meter for the more accurate EC reading as opposed to the workable ppm reading.

eSeasonGear (Google it in the US) has TDS, PH, EC, PPM testing pens at the lowest prices, btw.

 

[FreezerBoy]

TDS is PPMs ugly cousin. It too starts with an EC reading (there it is again, that pesky EC is everywhere) and converts to babble. Again, your garden doesn't care but, if you want other people to understand you, EC is the universal language.

 

[Befri]

I have the TDS meter with .5 conversation.

Does this mean that what my meter measures "800" then I take .5 of that
is my PPM?? Which is 400ppm at .5 conversation, correct???

I don't want to go and buy another meter.

 

[dongle69]

Conversion is to get back and forth from ec.
800 divided by 500 = 1.6 ec.