Recharging water softener resin with acid, rather than sodium

[woodenfish]

I believe the common water softener resin can be recharged using acid instead of sodium or potassium.

Many water companies have exchange tank service and they recharge these tanks in house and replace at home sites periodically. When they recharge in house, they use acid, not sodium as homeowners do.

To the best of my knowledge it is the same resin.

I actually have a sackful, about a quart of such resin. Can I use acid to recharge? Would this add no sodium but acidity to the discus tank?

Is this common?

[guille2007]

I heard it can be done, would be interested about the same, I would test it if someone is able to respond what quantity of muriatic acid would have to have the recharging solution.

[woodenfish]

Two common acids are HCL (in muriatic acid) and sulfuric acid.

When diluting sulfuric acid, add the acid to water rather than water to acid. This is critical if the acid is concentrated as the heat generated by dilution can boil the water and cause a serious problem. I will wear a face shield when diluting sulfuric acid.

I will try but I don't know what the concentration should be, definitely not concentrated so I will dilute both types of acid. The question is by how much.

For HCL, I plan to start by diluting ten times with RO water.

For sulfuric acid, may be 100 times to start to see if it works.

[Hans Kloss]

For sulfuric acid, may be 100 times to start to see if it works.

Do NOT use sulfuric. Its salt with Ca is poorly soluble in water and its microcrystals may damage your resin. Use muriatic instead at concentration of 2-3%. 10x diluted (about 4%) will be pretty fair too.
Hans

[woodenfish]

Thanks Hans.

After rinsing out thoroughly, there would not be any free running acid.

Whatever H+ released should be just to absorb the Ca++ and Mg++ etc.

For such I'll test this out to see if the tank water can get too acidic.

[guille2007]

If a resin was originally recharged with salt solution, can the next recharging process be switched to muriatic acid without any damaging?

[Hans Kloss]

If a resin was originally recharged with salt solution, can the next recharging process be switched to muriatic acid without any damaging?

Your resin cannot remember its last recharging process ;).
J-23

[guille2007]

Ok thanks Hans, will try next time with muriatic, and, how many times the acid solution can be used?, in case of salt solution the resin manufacturer I do use says to discard it after four times.

[Hans Kloss]

Ok thanks Hans, will try next time with muriatic, and, how many times the acid solution can be used?, in case of salt solution the resin manufacturer I do use says to discard it after four times.

I don't know, have always use it only once. Try to measure it's pH after first recharging process, if still below 1 than it may be used again.
J-23