Ionic exchanger as a water softening device for the water used in the house

Question

Hello,

We do have extremely calciferous water here. Our neighbours had a water damage now for the first time because of the calcination of the water pipes. I am wondering if the installation of an ionic exchanger is possible.

Short description of its function:
Calciferous water flows into the softener and there, the chalk is bound to the exchanger resin by the ionic exchanger. The “exhausted” exchanger resin is regenerated with a sodium chloride solution; after regeneration, the ionic exchanger resin is rinsed thoroughly and disinfected (how ever that is supposed to happen). The salt-chalk-solution goes into the wastewater sewage. The salt is added in form of granulate by the user. Unfortunately, I a have not found out yet how the brine (salt water) is produced in the exchanger, if the salt remains dry inside the storage container until the resin is rinsed with “fresh” brine about every three days.
This brings up the question of a potential germ risk.

Are there experiences with such devices?

Are you aware of any CF family that has such a device?

Thank you very much for your information.
Many greetings, K.

Answer

Dear K.,

Prof. Dr. Mathy of the Institute of Hygiene of the University Hospital in Münster [Germany] answered your question as follows:

“It is only necessary to decalcify waters that are harder than 20°dH [“dH” stands for “deutsche Härte” which means “German degree”; please see information about conversion of hardness unit below]. This should be checked beforehand.
In case of installing such a device you should only use products that have a DVGW certificate [DVGW is a German association; they also have an English website: see www.dvgw.de/english-pages/dvgw ]. This has to be pointed out to the installer/technical firm explicitely. The water should not be decalcified under 10°dH. Usually, this is done by mixing decalcified and not decalcified water. It is important that the system is run regularly and is also maintained on a regular basis so that the resin is not contaminated by germs. I would suggest to have the hygienic status checked several times a year.” [End of Prof. Dr. Mathys’ answer]

Best regards,
Annette Pfalz for ECORN-CF

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en.wikipedia.org/wiki/Hard_water (accessed on August 1, 2013)

“A degree of General Hardness (dGH or 'German degree (°dH, deutsche Härte)' is defined as 10 mg/L CaO or 17.848 ppm.”

Under the same link you also find a hardness unit conversion table under “Measurement”.

12.08.2013