Re: CaCO3 One of my tactics to adjust for optimum start-water conductivity has been to make a saturated solution and add a few mL to the distilled.
I am using the calcite form of CaCO3. It takes a very long time for it to go into solution in distilled water of 0.2 PPM. It took three months for it to get to 58 PPM, with undissolved solute remaining in the bottom of the bottle even though I had calculated the added solute based on the solubility listed in Lange's Chem Handbook . [ I think...it would be nice to have a pro looking over my shoulder]. Strangely, after I decanted the clear solution off of the remaining powder at the bottom of the bottle, the PPM rose another point or so. I suppose I got a few undissolved crystals when I poured it off. I'll bet adding a little HCl would speed things up, but that would insert yet another variable to be tracked. At present the solution reads 87.9 mS and 59.4 PPM [Sprite 6000 meter. As Ivan states, the PPM does not translate directly because the meter is calibrated with NaCl, and the conductivity is different. I need to study Ivan's method for converting between the two, and see how that reading fits with the conversion method. That link is a great resource Ivan. Thank you for pointing it out to us. I listened to Pink Floyd's "Time" again recently. How true. James Osbourne Holmes [email protected] -----Original Message----- From: Ivan Anderson [SMTP:[email protected]] Sent: Monday, September 27, 1999 12:45 AM To: [email protected] Subject: Re: CS>Standardization - A Call for Standards! Yes Mike, That looks like the one. 0 - 99.9uS = 0 - 100 ppm as silver. It turns out (as far as I can determine) that ppm as silver is almost equal to the reading in uS/cm^2 in water. I don't know why I haven't noticed this before!!! My reasoning: 99.9 uS = 50 ppm CaCO3 in water, given : http://www.goodwaterco.com/tds.htm Equivalent weight of CaCO3 = 50 (molecular weight / valencies, Ca+ 40.08 plus CO3- 60.01 = 100.09 divided by sum of valencies 2) , Equivalent weight of Na+ = 22.99 Conversion factor ppm as Na x 2.17 = ppm as CaCo3 given as above. Eqw Na 22.99 x 2.17 = 49.88 Eqw CaCO3 Eqw of Ag+ = 107.87 conversion factor ppm as Ag+ x 0.46 = ppm as CaCO3. (107.87 x .46 = 49.6) In other words a TDS meter reading in ppm as CaCO3 (TDS factor 0.5) doubled gives readout in ppm Ag+ (as I have noted before). What I hadn't noticed is that this is equal to the conductivity reading. Some confirmation is required I guess, but I am confident that this <light bulb burns brightly in thought bubble> will save me some work :-) Cheers - Ivan. ----- Original Message ----- From: M. G. Devour <[email protected]> To: <[email protected]> Sent: Monday, 27 September 1999 12:09 Subject: Re: CS>Standardization - A Call for Standards! > > > > The Conmet 1 (HI 98305) would be the unit of choice at $142.00 > > http://www.hannainst.com/products/testers/conmet.htm > > But more likely the DiST 3 at the miserly sum of $46.70 > > http://www.hannainst.com/products/testers/distw.htm > > > > Ivan!! > > Check out the Hanna PWT (Pure Water Tester) and see what you think > compared to the above? > > http://www.hannainst.com/products/testers/pwt.htm > > I thought it was pretty cheap and the range was set almost perfectly > for our needs. > > Let me know. This is the one I've been planning to get when I > upgrade. > > Mike D. > [Mike Devour, Citizen, Patriot, Libertarian] > [[email protected] ] > [Speaking only for myself... ] > -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] List maintainer: Mike Devour <[email protected]>
