masonicman
New member
What can I use if any, besides the manufacture's solution to calibrate my TDS meter?
TDS meter calibration
- Thread starter masonicman
- Start date
I generally do not believe that TDS meter calibration is necessary or useful when used to monitor RO/DI. There are, in fact, several different ppm TDS unit scales, and few reefers actually distinguish them anyway.
The thing that gets off in a TDS meter is not the zero point, but just the slope, so if 100 ppm TDS really reads as 110 ppm TDS, then at 1 ppm TDS, the reading will be 1.1 ppm TDS (which rounds to 1 ppm TDS).
With that being the case, there are two things that you use TDS for:
1. Monitoring RO performance by the ratio of TDS in to TDS out. That ratio will be unchanged by calibration.
2. Monitoring when a DI is depleted. Since I recommend replacing the DI as soon as you detect a rise in TDS, it does not matter exactly whether the TDS is 1.0 ppm or 1.1 ppm or 2 ppm or whatever when you detect it: it is time to replace the DI when it goes above 0 ppm.
That said, there are a few spring water brands that put TDS readings on the label that may allow inexpensive calibration if you want to do so, but do not want to buy a commercial standard. So you might check in the grocery store next time you are there.
The thing that gets off in a TDS meter is not the zero point, but just the slope, so if 100 ppm TDS really reads as 110 ppm TDS, then at 1 ppm TDS, the reading will be 1.1 ppm TDS (which rounds to 1 ppm TDS).
With that being the case, there are two things that you use TDS for:
1. Monitoring RO performance by the ratio of TDS in to TDS out. That ratio will be unchanged by calibration.
2. Monitoring when a DI is depleted. Since I recommend replacing the DI as soon as you detect a rise in TDS, it does not matter exactly whether the TDS is 1.0 ppm or 1.1 ppm or 2 ppm or whatever when you detect it: it is time to replace the DI when it goes above 0 ppm.
That said, there are a few spring water brands that put TDS readings on the label that may allow inexpensive calibration if you want to do so, but do not want to buy a commercial standard. So you might check in the grocery store next time you are there.
masonicman
New member
Thanks Randy. I wanted to email you this question directly but your email is blocked.
You're welcome.
Better to ask/answer it where others can see it anyway.
Happy reefing.
Better to ask/answer it where others can see it anyway.
Happy reefing.
