Getting pure water are good at any 1 time.
You will be happy on spending money on supplements and visit specialist often
I'm a cheapskate, I prefer to waste money on vacation, buying audio stuffs but never visit a specialist nor keep on buying supplements to stay healthy.
I only have a simple sand filter for outdoor unit and a carbon filter for drinking water(that boil it).
Everyday I wasted 30-45 minutes on nearby man made lake walking.

For industrial use, indeed they need clean water.
As for hospital, it is for hygienic reason.
Our body need some contaminant to stay healthy.

You may go to hardware shop to source such filter. Should be rm500-800. Then look for Indon/Bangla workers that know piping work. Pay them rm50.

A rm400-600 sand filter will do the job. Pressure drop high is due to the filter blocked, so doing back flush will do the trick

Just get the normal fiber sand filter type will do. Make sure it is using dark color, blue are nice
Using carbon or activated carbon filter are not a good idea
Using outdoor filter that boast can remove all impurities are more dangerous as it is a good algae and bacteria growth.
Carbon filter you need to regenerate it every now and then. You need to use acid and alkaline to do the job. Safer will be using vinegar and salt but less effective.

Basically any rm300-1000 sand filter are good enough already. If your incoming water too clean, it will promote algae growth on the stagnant parts.

Well, Syabas's water only using simple filtration and adding chlorine. So we need to filter any solid dirt before entering our house.
We only need "clean" water for drinking unless having skin issues on the water used for bath.

Some traces of chlorine won't give trouble, but getting pure H2O sure will make us spend more money on hospitals

Is good to get "clean" water where you filter out from outdoor unit as you are promoting green in the pipes
Like everybody says : go green