Before I start this post I would like to state that I really don't want this to become an argument between chemical / filter / electronic purification methods. the post is for those that have already chosen chemical purification.
With that being said................
A friend was admiring my gear and considering purchasing his own gear. He asked a lot of questions, which I answered enthusiastically. He was looking over my water purification tablets/drops/gear and asked, "How do you know how much to use?". I responded, "Just read the directions." He replied, "I am, it says dependent on temperature. So how do you measure the water's temperature?"
This never really occurred to me. So how DO you measure water temp in the field?
Different brand directions say that more chemical or time is needed with a decrease in temp or increase in turbidity.
At 41 degrees F (5 C) two 600 milligram tablets will be required.
Water to be treated that is colder than 68° F will require longer treatment time or increased amount of iodine.
Shake to mix. Let stand 15 minutes. If water is very cold, cloudy or tinted let stand 30 minutes.
Water temp and air temp can be two totally different things. Ground springs or mountain streams can be ice cold even on the average day. There are several options. Do you allow the water to warm naturally before treating? Do you intentionally use too much chemical/tabs and risk depleting your supply to quickly? Do you use the usual amount and risk parasites/illness? Do you use excessive fuel to boil the water pot by pot and wait for it to cool?
Here is my quick and easy solution.--- a temperature strip! I stuck one of these on my Nalgene bottle and put 2 thin coats of clear silicone over it to protect it. I can fill my bottle, instantly check the temp, and decide if any purification adjustments should be made.
If this solution appeals to you... Don't rush out to a major retailer, fish store, or pharmacy. Most of those strips only measure down to about 75 degrees (at which temp you wouldn't make any purification adjustments anyway).
I found these that measure down to 0-deg. I have the one on my bottle and one on my hiking pole for air temp.
So what tips or tricks do you use?