Hi, you've all probably talked about this subject before, but I'm having a hard time searching through the posts.

I was thinking about the redundant systems I have, mostly in the water area. I have Katadyn tablets, a pump filter, and fuel/pots to boil water. My question is, which system should take priority of use above the others? Same thing with fire: which to use first? Matches? Lighter? Sparklite? Etc.?

Is there a general rule of thumb? Basically I just go with what is easiest to do based on the equipment I have, but I'm wondering if that's the correct way to go about it.

It seem that answer depends on your condition and the resources on hand.

For water treatment:
I myself would leave the tablets as a last solution, since their supply is likely limited. If you have a pot (I carry the little cup that nests under a 32 oz. Nalgene wide-mouth) and sufficient fuel, then boiling is the most certain way to remove pathogens from water (full boil for at least one minute). If fuel is limited, then boiling is out.

Use of the filter should work fine - until the filter clogs. Does the filter remove viruses? If you are in a 3rd world urban area virsus could be a real concern. This could be a problem with a filter. The Katadyn Micropur tablets do kill viruses. In real nasty conditions (turbid water) you may even want to put Micropur tablets in filtered water. Unless the water is EXTREMELY clear, I'd recommend you at least filter it through a cloth before treating with Micropur tablets, just to try to strain out some of the organic materials.

For firestarting:
I would try the ligher first, then the sparker, and then the matches last. The lighter is easiest to use and should provide zillions of lights without running dry. Just make sure you don't leave it lit for too long at a time. For some lighters this will damage the working parts. The sparker should also provide hundreds (thousands?) of sparks, but is a bit more work than a lighter and depends heavily on the quality of the tinder. If you've got good tinder, a good sparker is nearly as easy to use as a lighter. I'd keep the matches as a last resort.

If you're also carrying a magnifying glass, then that could be used too, but only when sunny and not nearly as efficiently as the lighter and sparker.

For signaling:
Well, again, it depends on conditions. I'd make sure I had my orange space blanket laid out to attract attention. I'd also tie out my orange bandanna (such a thing as too much attention??). I'd blow on my whistle occasionally, but not so much as to wear me out. I'd likely only try to use a mirror if I actually see someone to target, but I suppose targeting the horizon wouldn't hurt. This should all be done while maximizing shelter and minimizing effort. This is all done assuming you've told someone where you'd be and when you were supposed to return, so, hopefully someone is actively looking for you.

If it's not an emergency, use the irreplaceable items last.

The following applies only for non-emergency situations:

I'd use the most difficult-to-use and/or non-consumable items first. In the case of water, that means boiling it. You haven't actually used up anything from your kit, so you're still fully equipped. If you started out with your tablets, one of your treatment options would soon be gone forever.

For fire, use the slower/more-difficult Sparklite with natural tinder now, save the lighter/cotton balls/matches for when you need a fire in a hurry.

Assume things will get worse, and save the best items for when you'll need them most.