Isle Royale Forums

Help, do we have to chemically treat filtered water? We have a MSR Hyperflow filter and a MSR Miniworks EX to filter water. We also have a Steripen for final treatment. We purchased the Miniworks EX for back up after reading all the mixed reviews on the Hyperflow filter.

No, you do not have to chemically treat filtered water. I have used a MSR miniworks on Isle Royale and it worked just fine, water tasted normal.

You have 2 possibilities: filter or boil (boil means heat water till the first couple of bubbles, you do not want to waste gas, once water reaches 100 deg Celsius, all is dead). And treating water chemically is not enough by itself, treating water chemically after filtering or boiling is unnecessary.

I have used a Miniworks and/or Gravity filter (ceramic catridge) nad have never had a problem.

I also started a similar thread here.... http://www.isleroyaleforums.com/viewtopic.php?f=3&t=777

I filtered and chemicallty treated on my 2004 trip, but only because it was a scout trip, and if a scout got sick for ANY reason, I didn't want the parents to think the leaders didn't do everything to keep their kids healthy. Normally though, just filtering is fine.

.

We're taking the Sawyer 4L gravity filtration system this year (http://sawyer.com/products/sawyer-compl ... er-system/)... it works great for larger groups. They also have a 2L version for smaller groups. It can filter 4 liters (or 4 Nalgene bottles approx) of water in 3-5 minutes without any chemicals or pumping... just fill up the "dirty" bladder, hang it, and relax until the "clean" bladder is full. For long, hot days on the trail without any water sources available... we've filled up the groups bottles to start the day... but then filtered another "clean" bladders worth and packed it as backup... and also filled up the "dirty" bladder and packed that to hang and filter along the trail later. That gives us 12 liters of water, if necessary.

I'm a reformed MSR Sweetwater user. I moved to a Sawyer Squeeze and haven't looked back.

I'm of the belief that there's no need to chemically treat filtered water on ISRO.

I too have never chemically treated water on Isle Royale, but just to be clear, almost all filters do NOT remove viruses. One should always maintain an awareness of where their water to be filtered is coming from. If it is down stream from, or nearby to, any sort of human activity (e.g. outhouse) there is a chance of viral contaminants that filtering cannot be guaranteed to remove, hence the extra careful precautions given by the NPS and others to also chemically treat. Modern backpacking filters will remove the Hydatid Tapeworm eggs and almost all bacteria but not viruses.

Tapeworm eggs are approximately 25 to 50 microns. Bacteria are 0.2 to 10+ microns. NPS recommends to either boil or chemically treat plus filter down to a minimum of 0.4 microns. The CDC recommends a 0.1 micron filter to stop bacteria. Viruses can be as small as 0.005 microns. For comparison, a virus at 0.005 microns is only 40 times bigger than an Oxygen molecule at 0.00012 microns.

A lot of chemicals can be in the 0.001 micron range which is why filtering can sometimes still leave bad tastes (or even be unhealthy in agricultural areas). It is why when algae blooms are flaring up you should stay clear as noxious chemicals are produced that no portable filter or boiling can remove.

Summary: If you're going to drink water from a puddle full of scat, don't just filter it.