I keep reading where ec should be like 1.6, but my vivosun meter doesn’t read it like that. It shows like 2100. How do interpret that? PPM seems to read correctly.
An EC of 2.0 = 1,000 PPM. They are different ways of measuring the same thing. The 2.0 EC, or 1,000 PPM, should be your target runoff measurement.
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Never mind. Figured it out. Just move decimal point 3 positions because it measures in us/cm.
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Millisiemens (mS/cm) vs Microsiemens (uS/cm).
Just move the decimal, you got it @Dexterado 
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Even in flower?
Correct
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So i need to keep the PPMs, in the soil, at 1000 throughout its entire life cycle for the best smoke in the end run? I am having difficulties understanding this
pH at 6.5 of course. I know this. I grow in soil
I dont know how i should feed? If it says to use Jacks 321 at 3g 2g 1g once a week and my ppm are 1000 then i skip a feed?
My plants are sitting in 1200-1800 ppm depending on the plant
I wont need to feed for a couple of weeks i guess? They are in their 1st week of flower
The 1,000 PPM target applies after you start feeding. It’s not really relevant until then since the PPM of the soil you would be using will likely be far higher than 1,000. It’s why we say don’t feed for 4 weeks from your most recent transplant. Once your soil is down to 1,000 PPM, then begin feeding and maintain the target 1,000 PPM.
Feed as necessary to maintain the target PPM.
You won’t be able to nail 1,000 every feeding. 1,000 +/- 200 to 300 PPM is fine. You’ll get better at it as your growing experience increases.
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Thank you… yeah, my mind is everywhere. I get myself confused. I never thought growing a plant out of the dirt could be so scientific. I am anxious to learn all of it that i confuse myself. My plants are growing and i didn’t kill one yet. They look healthy. Its a good thing i think everything through first before taking action and creating a problem that doesn’t exist. I am glad i have somwhere and someone that i can ask for information first. Thank you!
Keep at it, ask questions, and things will start clicking with experience and education.
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I have been multiplying ec x 700 for ppm due to another post on the forum I read once. It also said x 500 = tds. Have I been using the wrong math?
@OverallQuill80 It depends on who you’re talking with and what PPM chart they’re using.
A TDS meter only reads EC, it can’t actually count PPM’s, that’s why you’re doing conversions. PPM is totally the wrong metric to use to discuss TDS, because of all the confusion it brings with there being multiple charts depending on if it’s a US, UK, AUS, etc standard.
One person might be talking about PPMs from their 500 chart meter, and the person reading their post might have a 700 chart meter and use their PPM settings, and the EC’s will be completely different. It just leads to the very confusion you’re experiencing. I believe most around here use the 500 conversion chart, but I always state my TDS in EC and never use PPM when discussing numbers just to avoid this very thing.
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Thanks. I use a quality ec meter and do the math. I feel that it is better because I can calculate either scale except for the above mentioned problem.
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@Bubbala , it was my understanding that it all depends on what meter your using. What scale they used at the factory to calibrate that brand. The Apara EC60 use’s the 700 scale. I agree with you on using the EC reading. Universal.
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Most of the “hobby” grade meters have settings to change it to whatever you want. Ec 5 7
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@Low , I’m still not 100% sure on adding my numbers from my nutes and such. Say the number I’m shooting for is 1100 ppm. My water and silica is 200. Do I add nutes until it’s 1100(900 nutes) or add 1100 of nutes for a total of 1300? Just numbers I grabbed. And what about multi part nutes? Jack’s is what I’m using. How much of what part? Haven’t used 123 yet, just tap. Thanks
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I usually don’t take silica into consideration when mixing.
As for your tap, yeah I’d subtract it. But usually tap is made up of calcium, and magnesium and a lot of other things.
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Plants have EC thresholds. You have a limited amount of EC to use, what you fill it with is up to you (or the plant). Water, silica, calmag, nutes, pH adjustments, all count towards the total EC that your plant can handle. It’s a big reason for why many use RO water, to have more room on the EC plate for specifics the plant needs.
You can call it whatever EC you want as far as how much is silica and how much is nutes, but your plant sees it all together as one total sum of EC.
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@Bubbala , that makes it clearer. So when a nute manufacturer has on their schedule to feed 1100 at this time, that’s 1100 total everything. Not just 1100 worth of nutes.
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