I used to have an ionizer.. a good one will split the ions and turn the water more alkaline and also filter out the chlorine and other crappy shit.. the problem is they are expensive and the filters are very pricey
what you can do that is economical is buy something called ZEROWATER... it costs like $40.. you just change the filter every month or two and they cost like $8. it will filter out your water and it works
you can always verify if these filters work by doing a chlorine test on the water.. you never want to drink straight tap water as it is full of chlorine and other crap