I am wondering about measuring my soil. I have been growing in soil for about 6 years. I have always used the TDS measurement for my soil. Along with PH. But i have never gone by a TDS measurement. Is one any better than the other? Could i improve on my growing by changing to EC measurements? What are your experiences?
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It nothing but different ways of looking at the same thing. I measure PPM, but PPM’s equivalent values for TDS or EC would be just as accurate.
For example: an EC of 2.0 is equivalent to 1,000 PPM. The scaling is linear.
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Check your nutrient line and see which one it refers to. Mine are all TDS but when I first started hydroponics I checked both until I figured out it didn’t matter as long as you are within the range for your product.
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A bit confused in your question on whether you do or don’t use TDS, but here goes.
EC is Electrical Conductivity. Measuring the conductivity is the only way we have to calculate the amount of Total Dissolved Solids (TDS), which is commonly seen displayed as PPM, or Parts Per Million. pH doesn’t measure quantity, but quality in regard to how acid or base it is.
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My meter does not measure EC. It only measures TDS. I am thinking they are not the same. I am familiar with PH obviously.
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Your meter may display TDS, but it’s measuring EC. The meter can’t count, it can only measure electrical current.
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Thank you.
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Hope that settles things a little for ya. It’s really just a lot of letters and abbreviations that all express the same thing from different angles.
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It does. Thanks. I just realized my post say’s Why method do you use. lol Typo…Should have typed What Method? But you got the point. lol
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No prob… fixed it! 
Although… can you edit your titles with that Bergman’s Lab moniker?
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I couldn’t edit this one for some reason. I used to be able too. I’ve been a member here for a long time. I don’t know when that changed.
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I’m not able to edit mine either. Newer members sometimes think it indicates that I am a moderator. I am not.
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I have been here for about 6 maybe 7 years and you have too, i think. Something changed. I like the Lab. There were alot of good grpwers there and none of the newbie stuff you get on alot of other sites.
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I had a 4-year cannaversary a couple of weeks ago.
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I have no idea what triggers it, other than the “Regular” tag.
If it were by tenure, then it sure wouldn’t be me, I’m still just a newb.
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You can read the full tutorial on EC & PPM on the Coco for Cannabis website, but this paragraph pretty much sums up what others here have already said, just with a bit more detail.
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I’ve always pushed EC for the reasons illustrated in the pic on @Cap_Ron 's post.
There’s a pretty globally diverse crowd here in the forums, and using PPM to convey information is just asking for assumptions and confusion imo.
That chart @Ickey posted really lays out the variances. Following one persons PPM instructions could result in a disaster for somebody with a different meter.
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Correct me if wrong here. But I thought that ppm, (Parts Per Million), was the unit of measurement for TDS, (Total Dissolved Solids). So if a meter gives a TDS value it is using one of the three scales for the multiplier, is this correct?
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Exactly. So a PPM on a 500 scale meter would be a different EC on a meter with a 700 scale. The meter can only measure electrical conductivity, actually that’s what I’ve called it for the 30+ years I’ve used one in work and now this, a “Conductivity Meter”. Then it just does some math and spits out a TDS that’s displayed as how many Parts Per Million (based on whatever scale is programmed into it.)
I used to use one like this at work, and used it at home with my first DWC back in the 90’s, before I ever heard of charts or methods… guess I was on to something. Even a broken clock, right? 
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