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

[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.

Absolutely unscientific explanation . Sugar and other organic compounds form bonds that are like annoying soulmates, they leave nothing of themselves for others outside the bond, they share part of each other and that sharing, funnily enough, makes the bond the very strong.

 

[Ananas_Comosus]

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.

Thanks for the tip . How quickly will it spoil after opening?

 

[Loc Dog]

Thanks for the tip . How quickly will it spoil after opening?

No idea. Would ask the manufacturer, although it will probably last much longer since their goal is to sell as much as possible. Not sure if they sell different PPM reference solutions, but if you use 2 will be sure you are safe. I have PH references that are over 5 years old from GH. I pour enough to test into small mason jars and seal after use, so no evaporation. Also rinse testers with distilled water before and after every test, and change water every day or two.

 

[Growenhaft]

the ec value is strongly dependent on the temperature. if i mix my nutrient solution at 17°c to an ec value of 1.8... and heat this nutrient solution to 23°c, the ec value rises to 2.2 for me... just because of the fact that nutrient salts are mixed with it dissolve better in water as the temperature rises.

so if you take cold rainwater and warm rainwater and use the same amount of nutrients... then you get completely different ec values even though the water and the amount of fertilizer were the same... for this reason the soup should always be at the same temperature be cooked. for canna products this is 25°c... at this temperature the water has the best dissolving power to ideally dissolve nutrient salts.

 

[Three Berries]

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.

Off as in reading half of what it should be. Why would I want to use that? It may not be a linear error. And you can make your own calibration fluid with distilled water and table salt.

Using Electrical Conductivity and Total Dissolved Solids Meters to Field Test Water Quality

www.ndsu.edu

 

[Growenhaft]

or you simply use cocacola... that used to be our calibration fluid... cocacola always has the same ec and ph value at a normal room temperature of 22°c

 

[Ananas_Comosus]

No idea. Would ask the manufacturer, although it will probably last much longer since their goal is to sell as much as possible. Not sure if they sell different PPM reference solutions, but if you use 2 will be sure you are safe. I have PH references that are over 5 years old from GH. I pour enough to test into small mason jars and seal after use, so no evaporation. Also rinse testers with distilled water before and after every test, and change water every day or two.

Not to doubt your personal experience in the least , but most manufacturers that I have seen address the topic state that pH 4-7 buffers are good for 3-6 months and pH 10 is even less at about a month. I just went down the rabbit hole again and it seems that conductivity solutions go bad qualitatively (spoil) and drift for reference purposes even faster than pH buffers. Apparently it is good practice to dispose of solutions at 30-60 days. Of course, labs have different considerations than home growers but even user consensus seems to be that 6 months opened is a lot to ask for. Which is why I have been hesitant to get a pH meter as I would be willing to do the necessary calibrations and store it properly but the high cost and short life of the associated consumables is putting me off .

 

[Ananas_Comosus]

the ec value is strongly dependent on the temperature. if i mix my nutrient solution at 17°c to an ec value of 1.8... and heat this nutrient solution to 23°c, the ec value rises to 2.2 for me... just because of the fact that nutrient salts are mixed with it dissolve better in water as the temperature rises.

so if you take cold rainwater and warm rainwater and use the same amount of nutrients... then you get completely different ec values even though the water and the amount of fertilizer were the same... for this reason the soup should always be at the same temperature be cooked. for canna products this is 25°c... at this temperature the water has the best dissolving power to ideally dissolve nutrient salts.

Please tell me if I am wrong because I absolutely believe this to be the case but don't ATC capable meters eliminate that consideration by factoring in temperature in the calculation?

 

[Ananas_Comosus]

or you simply use cocacola... that used to be our calibration fluid... cocacola always has the same ec and ph value at a normal room temperature of 22°c

LOL I always like DIY. I actually thought about it that If I knew the EC of manufactured liquids I could use those to get an idea of accuracy, but contamination of the probe and all that