Is my EC meter bad or Something else is going on?

[Ananas_Comosus]

My cheap EC meter seemed fairly reliable until recently. I have been blessed with an abundance of rain that I have been able to store in a barrel and use as the base of my feed. The EC of the unamended rain water is 0.0. When I add my nutrients the EC should be 1.6. Last week and this week when I made the feed it read 2.1 EC. I had to top off my bucket to get it down to 1.6 and both times I used the same amount of water. I plan on getting calibration solutions to verify but is the meter bad or is something else going on? Two known readings, distilled water and my tap water, remain the same. Is this an issue where the results are repeatable but not accurate?

 

[Creeperpark]

Lucky you getting rain! Since meters use electrical conductivity using rainwater or distilled water you can get false readings because of its purity. There's nothing in the water for the current to flow through. That's what makes rainwater so special.

Heres how to check your meter. Switch your EC meter to ppm so you can get precise readings. Get some rainwater or distilled and some tap water and get a reading on both. Write down the ppm of both waters' and then draw a measured ppm out of the tap water and add to the rainwater. If the added amount brings up the ppm exactly as it subtracts from the other water then your meter is fine. IF there is a miss reading between the two waters the ppm will be off and your meter is no good.

 

[Ananas_Comosus]

Lucky you getting rain! Since meters use electrical conductivity using rainwater or distilled water you can get false readings because of its purity. There's nothing in the water for the current to flow through. That's what makes rainwater so special.

Heres how to check your meter. Switch your EC meter to ppm so you can get precise readings. Get some rainwater or distilled and some tap water and get a reading on both. Write down the ppm of both waters' and then draw a measured ppm out of the tap water and add to the rainwater. If the added amount brings up the ppm exactly as it subtracts from the other water then your meter is fine. IF there is a miss reading between the two waters the ppm will be off and your meter is no good.

Thanks for the good info and tip

 

[troutman]

Maybe, get an EC calibration solution.

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[DARKSIDER]

Check the batteries and probe it may want cleaning

 

[Three Berries]

The cheap meters are junk and what good is calibration fluid if the meter is off?

I'm just about banned on eBay for buying anymore as I sent them all back as inaccurate.

Same with those cheap humidity temp digital meters. I bought a lot of ten and they were ALL off 5% low. I had to go around and around to get them to refund my money. They wanted me to accept a device that gives false readings. I told them I was just going to throw them away as they didn't want them back. << that's a big clue.....

I did just get two Inkbird TDS pen meters that actually read within a point of each other on my well water. I had a Apera one but it was too accurate, would not go over 1000ppm either.

 

[Ananas_Comosus]

Maybe, get an EC calibration solution.

​

Shopping now. Do you happen to know the general shelf life after the container is opened? I want to know if it make sense to get the sachets or a bottle.

 

[Douglas.Curtis]

Did you happen to test the rain water directly for any changes? Chemtrails are a proven and documented 'feature' of the sky now and the list of additives is long and growing.

 

[Ananas_Comosus]

The cheap meters are junk and what good is calibration fluid if the meter is off?

Do you mean off as in not turning or off as in inaccurate readings? If you mean inaccurate readings it will allow you to confirm how much it is off by and if the results are consistent you can take that offset into consideration when using the meter (depending on the application of course). Also if the the results are repeateable, and the meter has adjustable calibration the meter can be set to the EC of the fluid and used fairly reliably as long as calibration is checked regularly and drift is not occurring.

 

[Ananas_Comosus]

Did you happen to test the rain water directly for any changes? Chemtrails are a proven and documented 'feature' of the sky now and the list of additives is long and growing.

Apart from measuring EC both times, which was 0, I am unable to test the rain water further

 

[Ananas_Comosus]

Lucky you getting rain! Since meters use electrical conductivity using rainwater or distilled water you can get false readings because of its purity. There's nothing in the water for the current to flow through. That's what makes rainwater so special.

Heres how to check your meter. Switch your EC meter to ppm so you can get precise readings. Get some rainwater or distilled and some tap water and get a reading on both. Write down the ppm of both waters' and then draw a measured ppm out of the tap water and add to the rainwater. If the added amount brings up the ppm exactly as it subtracts from the other water then your meter is fine. IF there is a miss reading between the two waters the ppm will be off and your meter is no good.

Tap water ppm (0.5 factor) 552
Distilled water ppm 6

100 ml tap water + 100 ml distilled water = 264 ppm

Sounds about right? (stated accuracy is +/-2%)

Edit: Just calculated and if the right calculation is to add 552 to 6 and divide by two the accurate ppm should be 279. 269 is off by 5.68%

 

[revegeta666]

Hi. You didn't say what brand of nutrients you are using, or I missed it. If you are using Biobizz, Bio Canna, or some other "organic" bottled nutrients, the EC meter will give you unaccurate results. It just doesn't work well.

 

[Ananas_Comosus]

Hi. You didn't say what brand of nutrients you are using, or I missed it. If you are using Biobizz, Bio Canna, or some other "organic" bottled nutrients, the EC meter will give you unaccurate results. It just doesn't work well.

This is my own DIY knockoff of a popular Coco formula using high purity base chemical fertilizers and distilled water. I am wondering if the commercial nutrients add some kind of unlisted buffer that makes readings in low EC water like distilled or rain water more accurate.

 

[Ananas_Comosus]

Hi. You didn't say what brand of nutrients you are using, or I missed it. If you are using Biobizz, Bio Canna, or some other "organic" bottled nutrients, the EC meter will give you unaccurate results. It just doesn't work well.

I always wondered about this and thought it might be the case. Why don't organic nutrients give accurate EC? I read earlier that sugar doesn't change EC. Which I find amazing since molasses kicks EC high relative to volume used.

 

[revegeta666]

I always wondered about this and thought it might be the case. Why don't organic nutrients give accurate EC? I read earlier that sugar doesn't change EC. Which I find amazing since molasses kicks EC high relative to volume used.

You're asking the wrong guy haha. 10 years using both brands I mentioned. I only know this from experience. Not sure about the scientific explanation.

 

[unnamedmike]

1gr of NaCL (Table salt) in 1L of pure water = 1000ppm

 

[Ananas_Comosus]

You're asking the wrong guy haha. 10 years using both brands I mentioned. I only know this from experience. Not sure about the scientific explanation.

I like people who know to say "I don't know" .

 

[Ananas_Comosus]

Sorry, Double post

 

[acespicoli]

Lucky you getting rain! Since meters use electrical conductivity using rainwater or distilled water you can get false readings because of its purity. There's nothing in the water for the current to flow through. That's what makes rainwater so special.

Heres how to check your meter. Switch your EC meter to ppm so you can get precise readings. Get some rainwater or distilled and some tap water and get a reading on both. Write down the ppm of both waters' and then draw a measured ppm out of the tap water and add to the rainwater. If the added amount brings up the ppm exactly as it subtracts from the other water then your meter is fine. IF there is a miss reading between the two waters the ppm will be off and your meter is no good.

Brilliant we need more people that use their heads for more than a hat rack, very intelligent input. Thanks for sharing I had a similar interest in calibration

 

[Loc Dog]

Shopping now. Do you happen to know the general shelf life after the container is opened? I want to know if it make sense to get the sachets or a bottle.

I would buy bottle for most accurate. My RO water is 35 PPM and if volume is slightly off you will lose accuracy. Also for PH get 4 and 7. I only used 7 and batteries were dying and kept adjusting to 7 and was way off right before batteries finally died.