Hoping someone could give some insight. Thank you very much in advanced.

1. Landed double storey.
2. 2 Adults and 1 Baby
3. No kidney disease or related
4. Yes, replacement filter or easy maintenance should be doable.
5. Prefer 1 time purchase
6. Budget about 1.5k
7. Not Yet. Looking for Internal and External
8. Hot water function is not a must. But it is a plus. I have a Youmi instant water heater that could dispense hot water from a water tank.

Thanks again in advanced guys.