TDS in RO water

[screebo]

OK..................logged and noted. Now, what it your favorite chemical test for calcium? The one I use is pretty clear in results (going from pink to blue when appropriate level reached) Still, I thought it would be great to have a meter. Have you done comparitive studies to log your observations? Just how far "off" have you found the resulting readings on the Pinpoint to be? More than 5-10 points? It wasn't cheap so I'll appreciate knowing just what I'm getting for the money.

Thanks!

 

[GreshamH]

never kept a log of how off the are but when I have put several units side by side none read the same. I don't use meters for CA/ALK/MG. I use salifert and Elos test kits. Norm likes API using a syringe from Salifert IIRC>

 

[aalhait]

Are you sure your TDS meter is accurate!

My tap water reading is 220 or so! My RO out is around 5-6.

Perhaps you need a new TDS meter.

 

[yardartist]

Are TDS meters portable enough to bring to the meeting to test water if samples were brought?

 

[GreshamH]

Some are as small as 3.5" x 2" x .5" Others are like PH pens... some are as large as a wall socket... etc etc

 

[screebo]

Frankly, after a while as long as things are doing well I don't do things like test my TDS in the RO water. My meter is very portable and has been around for quite a while. I do think it's reasonably accurate but I've not calibrated it since acquiring it long ago. Same deal with my PH meter. It seems very accurate when comparing to chemical test but I haven't calibrated it ever. It follows the PH swing from morning to night with a low of 8.0 in the AM and a high of 8.5 in the early evening. CA needs boosting every few days to maintain 440. PH stays stable most of the time but occasionally needs boosting/buffering.

Thanks for the tip, Gresham. I do believe in objective comparison and have been doing chemical tests so long that I'm not about to give up now. I just want to use the best tools availble to me and be as lazy as practical.

 

[yardartist]

If I brought a water sample, would someone bring a meter a week from today?

 

[GreshamH]

A PH unit should be calibrated every use./ Never depend on it otherwise. I bet if you checked it against a standard it would be off.