I was talking w/ my chemist/reg. santarian father re: the Aqua Mira not killing Giardia thread, and the normal commercially available treatments on the market.
His recommendation (industry standard for water purification plants) was 1oz bleach or iodine per 10 gallons untreated (but generally sediment free) water. This works out to 7 drops of 5.25% Sodium Hypochlorite (Bleach) per guart/liter of water. Probably 6 drops/quart for Chlorox Ultra. His recommendation was no less than 5 drops for very clean water sources (assuming you're going to treat them). Wait 1/2 hour as usual.
He also told me how to get rid of that nasty bleach/iodine taste, though!
Sodium Thiosulfate is a non-toxic, readily available, reductant that will instantly remove the taste but reacting the chlorine/iodine out of the water. Read the wiki article for information.
This is used all the time in water purification plants if too much chlorine remains in solution. Same for swimming pools. It's also available in any pet store as chlorine remover for aquariums. You can eat the pure powdered form, so just experiment to see how much it takes.
He's going to make me up a small bottle of 10% solution, it'll take less than 1 drop/quart to do the job. Oughta last me about a lifetime for free .