I'm pretty sure you need something more sophisticated than an inline cartridge filter to remove the stuff that'll make you ill, as you say boiling automatically get's done when making hot drinks or maybe UV treatment may do it? I think I've read in the past somewhere that silver also kills bugs but I guess we're going to be getting really expensive now!Fitted an inline cartridge filter on pressure hose after the pump for the whole system to take out nasties.
Don't tend to drink tank water unless boiled. Change the filter every 6months or so, not expensive.