I have hard water in my house. All the taps have tartar around. It generates some problems in some of my home appliances so I have bought polyphosphate salt but when I boil water I don´t get the expected results.

I´m looking for some product or filter that would make the water in my house better for drink and use. That´s is why I´m evaluating to install a filter with polyphosphate salt or a floating dispenser (like a buoy).

I´m now trying to make a test before installing the floating dispenser I have recently bought in my water tank so, this is what I have done:

First I have filled a pan with water and boil it until it got empty and this was the result:


Then, I have use the floating dispenser in a pan with polyphosphate salt for 30 mins. After that I took out the dispenser and boil it until it got empty. This was the result:

After 30 min of Siliphos

It seems like there is no difference.

How can I make a better measurement or treatment? Is this the right product for my problem? 30 minutes is enough to the polyphosphate salt? Do you think that will be better a floating dispenser or the filter with that product? Maybe I have to buy another kind of filter?


1 Answer 1


Most drinking water has residue like what you are showing. Boiling water shows there are ions in the water, but it does not show what kind of ions are present. Boiling water is practically useless when determining scaling potential and it is not safe to do using cooking pots and pans. Part of the reason laboratory equipment is more expensive than cooking pots and pans is because lab equipment has much better fire prevention measures. Boiling down water in this manner has the potential to start a fire.

pH is a better measure for scaling potential. If you want to get technical, water pH is used to determine the Langelier Saturation Index or the Ryzner Index which are indicators of scaling potential.

Your water is probably too alkaline. Alkalinity and acidity need to be balanced because if water is too alkaline then too much scale forms; however, if the water is too acid pipes corrode.

For a household, filtering water with an activated carbon filter first, then an ion exchange filter might work. Ion exchange filters contain a resin which exchange scale forming ions like calcium with ions like sodium. These filters can be easily fouled by organic material, so the organic material will need to be removed by something like an activated carbon filter.

  • $\begingroup$ Thank you @Agriculturist! I have updated my question to be more clear. As I understand from what you said I have to look for another type of filter and not just Siliphos product. $\endgroup$
    – Ignacio
    Commented Jun 25, 2020 at 16:48
  • 1
    $\begingroup$ @Ignacio This question should probably be edited to remove mention of brand names. On this exchange calling a compound "bleach" is appropriate, but calling it "clorox" is not. $\endgroup$ Commented Jun 25, 2020 at 19:27
  • $\begingroup$ Thanks again @Agriculturist! I wasn´t sure how to call that product and that is why I put the name. If you suggest me another name I will change it (polyphosphate salt perhaps?). $\endgroup$
    – Ignacio
    Commented Jun 25, 2020 at 19:31
  • 1
    $\begingroup$ That name is better. Polyphosphates bind to metal ions and metal surfaces so as to inhibit scale formation, but they do not remove those ions from the water. There are a number of factors which influence the effectiveness of polyphosphates and there are multiple types of polyphosphates. Figuring all these factors out would require testing the water in a lab set up to do that type of testing and someone familiar with that particular technology. $\endgroup$ Commented Jun 25, 2020 at 20:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.