David — if you double the treatment time — say from 4 max to 8 whole hours, you should be able to half the dosage — and thus 1 tablet for 2 liters instead of just 1 liter.
Brian — I thought you and I went through this before, but maybe I just got you mixed up with someone else. Anyway, in my (and others') conversation with AquaMira rep — the chlorine dioxide in tablet form is 3-4 times MORE than in liquid form. That's why:
1. AM liquids ONLY mention treatment against bacteria — and is COMPLETELY SILENT about treating protozoa.
2. AM liquids are not EPA registered (becaue they couldn't be and thus are forbidden from mentioning protozoa on their packaging / directions).
3. AM (or Micropur) brand tablets are EPA registered — and are allowed to mention treatment against all three: bacteria, viruses and protozoa
The AM rep said one could safely use AM liquids to treat protozoa as well — by QUADRUPLING the dosage.
So, doing the math…
But I no longer use chlorine dioxide anymore. Even with tablets, the 4 hour max. time (for cold water) is too long for me — and I don't really want to be guessing whether 30 minutes is enough or should I leave it for another hour or two…
I now use a combination of chlorine (household bleach) to treat only viruses and bacteria (which only requires 20 minutes) — then drink (suck) water through my AquaMira Frontier Pro filter to block the bigger and chemically harder to kill protozoa.