I see you're in India! I'm not sure how that product works but the reviews look promising? The hard water softeners I was talking about rely on city water coming into your house under pressure. Not a tank system that needs to be filled. So I really don't know for your case. But as long as it removes calcium and magnesium it'll make the water soft.

Water softener is a must if you live in hard water areas. You can look up your towns water hardness index with a quick Google search. A water softener is what you are looking for, and if you know basic plumbing you can install one for around $500. It takes salt that you can get from anywhere. It's amazing. It will make the water feel slightly slimy but no more hard water stains, clogged bidets and showerheads will look clean. When you do need to clean all the hard water stains off, use vinegar. You need an acid to get the stains off and this works really well. You can even remove showerheads and dump them into a bucket of it overnight.