The only water purification I've done is when on backpacking trips. I always purified it right before I was going to use it (a couple of hours before use), not ahead of time. I never used bleach, and that may not dissipate fast enough. I used iodine a lot. That did leave a slight taste, but not so bad that you couldn't use the water. There were other tablets that you could use - specific water purifying tablets - that did not leave any taste. Those were fine for backpacking, but I would think them too expensive for larger scale household use. There is also something called a "LifeStraw" that does a very good job of filtering out bacteria and parasites. It does not do viruses though. But if you're filling your water bottles from a safe source to begin with, I wouldn't think viruses would be a problem. You drink through this device (like a straw), so it's not for batch water purifying. They're cheap. I have a few around the house for emergency use - mostly after a water main break somewhere - that results in a "boil water" directive from the water company. We drink bottled water (from those 5 gallon barrels) so we don't have to worry too much about these "boil water" directives, but the LifeStraws are there for additional options and backup.