28 people, the leader said that filters were not necessary since there were potable water sources along the way. On a day when we were hiking 10.1 miles, we only had potable water at the start and at the end. For lunch we stopped at a lake and I was the only one with a filter, my Platypus gravity filter. It was in the 80's and many people were out of water at lunch time. I filtered 16 liters of water for the group. Had I not brought my filter, we would have had some serious dehydration. The lesson here: just because potable water is available, it may be a very long distance between water sources, bring an alternative. Filters do clog, you need a backup.
5-day 30 mile trip:
We had 8 boys and 7 adults. Every boy had a Dad (I had two boys on this trip) and every family had a filter except one (we started with 6 filters for 15 people). One family had a "Triton" gravity filter which was nearly useless (it took about an hour to filter a liter), now we are down to 5 filters for 15 people. One of my boys got sick and he and I left early. I left my platypus with the family with the ineffective filter since I only had one day of hiking to get back to the car. One family that got separated from the rest of the group, but had their filter so they were OK.
On another trip we were getting water out of the surf zone in lake Michigan and there was a lot of algae and some of the filters got clogged. The Platypus came to the rescue for those with clogged filters.
So, the bottom line is filters get clogged or break, if you have a large group, they may not always be together 100% of the time. Sometimes people may need to leave early for medical reasons. I would make the policy like this: 1 filter/sterilizing device per 3 people maximum. Every person should carry some tablets as a backup. Of course, boiling water is your 3rd option, but you may not always have enough fuel for that.
Backpacking and Sharing the load - Water purification
in Camping & High Adventure
Posted
Here are some of my recent experiences:
2-night shakedown trip:
28 people, the leader said that filters were not necessary since there were potable water sources along the way. On a day when we were hiking 10.1 miles, we only had potable water at the start and at the end. For lunch we stopped at a lake and I was the only one with a filter, my Platypus gravity filter. It was in the 80's and many people were out of water at lunch time. I filtered 16 liters of water for the group. Had I not brought my filter, we would have had some serious dehydration. The lesson here: just because potable water is available, it may be a very long distance between water sources, bring an alternative. Filters do clog, you need a backup.
5-day 30 mile trip:
We had 8 boys and 7 adults. Every boy had a Dad (I had two boys on this trip) and every family had a filter except one (we started with 6 filters for 15 people). One family had a "Triton" gravity filter which was nearly useless (it took about an hour to filter a liter), now we are down to 5 filters for 15 people. One of my boys got sick and he and I left early. I left my platypus with the family with the ineffective filter since I only had one day of hiking to get back to the car. One family that got separated from the rest of the group, but had their filter so they were OK.
On another trip we were getting water out of the surf zone in lake Michigan and there was a lot of algae and some of the filters got clogged. The Platypus came to the rescue for those with clogged filters.
So, the bottom line is filters get clogged or break, if you have a large group, they may not always be together 100% of the time. Sometimes people may need to leave early for medical reasons. I would make the policy like this: 1 filter/sterilizing device per 3 people maximum. Every person should carry some tablets as a backup. Of course, boiling water is your 3rd option, but you may not always have enough fuel for that.