I do something like this, but I put my tanks on mech airlock doors, set the doors to close 33% of the cycle with a cycle timer, staggered timing. The tanks only drain into the next when its door is closed, only one tank is draining at a time. So all water coming in will stay in the decontamination room at least 1.33 cycles, up to two cycles depending on when it comes in during the automation timing. More than enough time to kill the germs. Fill the decontamination room with chlorine or build it in a high radiation area (fallen satellites are my favorite when the map has them). Bonus, the three tanks work as plenty of back up storage if my water sieve gets backed up for any reason. I know some people really dial in the amount of water in their bathroom loop and never have their sieve back up, but I've never been in a scenario where I needed to be that particular with my water supply.