Rainbows, yes, but also MOONbows! The conditions have to be just right so you'll have to be pretty lucky. A friend of mine has spent most of his life here and has only seen 3 of them. But 3! They do exist. It makes scientific sense, I've just never thought of it before.
A friend of mine in Monteverde, Costa Rica just saw one the other night! She said it was a windy night with a full moon. Incredible!
Seeing a moonbow (also known as a moon rainbow or lunar rainbow) are the same as a regular solar rainbow, but using moonlight instead of sunlight refracting off water in the air.
For the conditions to be right, you need a full (or almost full) moon, water droplets in the air (Monteverde is commonly misty), the moon a low angle across from the mist/rain, a dark sky (little light pollution),
They have been known to be seen in:
Cumberland Falls, Kentucky - famous for regular moonbows
Yosemite Falls, California - especially in spring with heavy snowmelt
Victoria Falls (Zambia/Zimbabwe), Hawaii, Costa Rica - it's rare, but they've been experienced in these locations, too.
SteriPEN Ultralight UV Water Purifier
This is not quite as good as Grayl , but it's small, lightweight and rechargeable. It sterilizes the water, cleaning out bacteria, viruses and protozoa, but does not filter out any turbidity so it's fine for hotels, but maybe not streams. It also needs a glass or a wide mouth bottle.
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