Aquatabs 397mg (100) review

What it is and who it suits

Aquatabs are chlorine-based tablets, not iodine. The 397mg size is a larger tablet than the 49mg Aquatabs we also list, so it is meant for a container of water rather than a single bottle. Our tracked listing is Amazon ASIN B09FFQN924, a 100-count pack.

It suits a household that stores water at home and wants a back-up disinfectant for a larger container if the tap becomes unsafe. This review is researched, not tested. It relies on Aquatabs' own page and on guidance from CDC, EPA and Ready.gov.

Why this review gives no dose

We could not confirm a dose for this tablet from a source we trust. Aquatabs' own dosing page lists other tablet sizes, none of them 397mg. We found no label or regulator figure for it, so we do not repeat any retailer's number.

CDC's guidance is clear on what to do instead: follow the instructions on the label or package of chlorine, chlorine dioxide or iodine tablets or drops, because chemical disinfectants are made to disinfect specific amounts of water. Read the pack you receive before an emergency and write the dose and wait time on the container.

What the maker says

Aquatabs' page says its tablet is added to drinking water to kill most harmful micro-organisms, dissolves clear within minutes and disinfects the water within 30 minutes. It reports reductions of 99.9999% for bacteria, 99.99% for viruses and 99.9% for Giardia cysts, tested as per the US EPA water purifier challenge test.

The page also says that if water is cloudy or has visible particles, you should pre-filter it through a clean cloth first, then stir, cover and wait 30 minutes. Those steps match CDC's advice to filter cloudy water through a clean cloth, paper towel or coffee filter, or let it settle, before disinfecting.

What chlorine tablets cannot do

CDC says chemical disinfectants kill viruses and bacteria but may not kill parasites, and that chlorine tablets will not kill Cryptosporidium, while chlorine dioxide tablets will if you follow the instructions. Aquatabs' own chart shows a Giardia reduction, not a Cryptosporidium claim, so do not assume this tablet covers it.

CDC also says boiling is the best way to kill germs in water, and that you cannot make water containing fuel, toxic chemicals or radioactive materials safe by boiling or disinfecting it. If you know or suspect that, use bottled water or another source and contact your health department. Our make water safe guide and boil water advisory guide walk through the order of options.

How it compares with the other picks

Our water purification tablet comparison also lists the smaller 49mg Aquatabs, plus two Potable Aqua iodine products. The 397mg tablet is the one for bulk water. The 49mg size is the better fit for a single bottle. The iodine tablets suit short trips, but CDC says people who are pregnant or have thyroid problems should avoid iodine-disinfected water.

One point of difference: Ready.gov's water page recommends plain household bleach and says other water treatment products sold in camping or surplus stores are not recommended, while CDC accepts tablets used as directed. Keep unscented bleach in your plan too, and see how much water to store.

Verdict and who should skip it

A workable back-up for treating stored water in bulk, provided you have the label in hand and you treat it as a second line after stored bottled water. Skip it if you only treat single bottles, if you will not read the dose instructions, or if your worry is Cryptosporidium or chemical contamination, where it does not help.

How many tablets do I use per gallon?

We do not give a number, because we could not confirm one for the 397mg tablet from the maker, EPA or another trusted source. CDC says to follow the label or package of any tablet, since disinfectants are made for specific amounts of water.

How long do I wait before drinking the water?

Aquatabs says its tablets disinfect water within 30 minutes after stirring until dissolved and covering the container. Always use the wait time printed on the pack you hold.

Does it remove chemicals or fuel from water?

No. CDC says you cannot make water containing fuel, toxic chemicals or radioactive materials safe by boiling or disinfecting it. Use bottled water or another source and call your health department.

Will chlorine tablets kill Cryptosporidium?

CDC says chlorine tablets kill most germs but will not kill Cryptosporidium, while chlorine dioxide tablets will if used correctly. Boiling is the best method when it is possible.