Hermit
fuddle
My city water report gives 'typical' readings for a year. pH 10.81
http://meanderwater.com/Portals/MeanderWater/Typical Water Analysis - January 2012.pdf
This is the best information I've been able to find on high pH and RO. Anyone have better they can point me too?
http://www.membranes.com/docs/paper...ing High pH - High Temperature Wastewater.pdf
"At high pH, the membrane retains its negative charge. However, as pH increases and the hydroxyl ion concentration increases, the carboxyl groups on membranes surface are repelled or opened and the membrane swells. This swelling effect increases the passage of certain ions. Hydroxyl ions (OH-), for example, pass through the membrane more readily than chloride ions (Cl-). This is evidenced by a negligible decrease in pH in the permeate of a produced water RO systems when running at high pH. At one site running at pH greater than 10.5, the pH in the permeate of the RO system actually increased to more than 11.
Along with the high passage of hydroxyl ions, an increase in the passage of sodium is also seen. The sodium acts as the counter i on to the hydroxyl ions in order to maintain charge neutrality in the permeate."
I just put in a new system. I had a pH meter and got a TDS meter when I got the system. The system is new and supposedly the TDS will decline for a while, but I'm getting about 80% reduction now. I'm not sure it is going drop that much more. pH drops some but I haven't done too much with it yet. I'm thinking I might have to drop the $35 or whatever Ward Labs charges now to see what I have in a month or two.
http://meanderwater.com/Portals/MeanderWater/Typical Water Analysis - January 2012.pdf
This is the best information I've been able to find on high pH and RO. Anyone have better they can point me too?
http://www.membranes.com/docs/paper...ing High pH - High Temperature Wastewater.pdf
"At high pH, the membrane retains its negative charge. However, as pH increases and the hydroxyl ion concentration increases, the carboxyl groups on membranes surface are repelled or opened and the membrane swells. This swelling effect increases the passage of certain ions. Hydroxyl ions (OH-), for example, pass through the membrane more readily than chloride ions (Cl-). This is evidenced by a negligible decrease in pH in the permeate of a produced water RO systems when running at high pH. At one site running at pH greater than 10.5, the pH in the permeate of the RO system actually increased to more than 11.
Along with the high passage of hydroxyl ions, an increase in the passage of sodium is also seen. The sodium acts as the counter i on to the hydroxyl ions in order to maintain charge neutrality in the permeate."
I just put in a new system. I had a pH meter and got a TDS meter when I got the system. The system is new and supposedly the TDS will decline for a while, but I'm getting about 80% reduction now. I'm not sure it is going drop that much more. pH drops some but I haven't done too much with it yet. I'm thinking I might have to drop the $35 or whatever Ward Labs charges now to see what I have in a month or two.