DIY 1500 ppm TDS calibration solution

[mtfish]

I have a Hanna HI9813-6 meter that has a "check" button to check TDS. It specifically needs 1500 ppm solution. Can someone come up with a homemade solution that will be 1500 ppm? I have good scales to get accurate measurements.
Thanks

 

[Randy Holmes-Farley]

What do you use the meter for?

If it is for RO/DI, then it would be fine to use a sodium chloride standard, and 1500 ppm = 1500 mg/L = 1.5 g/L.

So dissolve 1.5 g of table salt in 1 l of Ro/DI water. :)

 

[mtfish]

Thanks Randy. I am actually using the meter to grow strawberries in an indoor hydroponic system, so need to calculate how much nutrients to add. I've never had any luck growing them outdoors in my area. Would the table salt still be the correct salt for my solution?

 

[Randy Holmes-Farley]

Thanks Randy. I am actually using the meter to grow strawberries in an indoor hydroponic system, so need to calculate how much nutrients to add. I've never had any luck growing them outdoors in my area. Would the table salt still be the correct salt for my solution?

Yes, it’s fine for that purpose. The issue is there are many different standards for converting conductivity (an absolute measure) into ppm tds, which depends on the ions one is measuring.

If you want to dig deeper, I discuss those issues here:

What is TDS? by Randy Holmes-Farley - Reefkeeping.com

See table 2. That calibration will match the tds NaCl column.