I am looking up how much alum per gallon of water. Nuts and Co. sells alum by the pound.
I don’t think you need much alum. Per the Swamper’s instructions formula to flocculate silty water:
“2 teaspoons of alum in a 1 liter Nalgene type bottle. Fill with water and shake it up. Fill your settling bucket with river water. Add 2-3 capfuls of alum mix to the settling bucket. Vigorously stir 15 seconds in one direction using a circular motion to create a center whirlpool. Stir in the other direction 15 seconds. Sediment should mostly settle out in 45-60 minutes.”
You can find Alum in with the spices in the grocery store; it’s commonly used in making pickles.
Given that 2 teaspoons dissolved in water saturates one liter, and that liter of alum water is then dispensed in small amounts into a settling bucket, I think that little spice jar will last a long time.
Especially since settling and filtering the Green would be my last choice in potability, after what I bring in dromedaries, what I can filter from up side-canyon springs and, if I’m lucky, what I can catch off the parawing if it rains.
I could have filled a bathtub with what came off the low V sides of the parawing last spring.
BTW – I had been looking (and looking, and looking) for the perfect firepan. By permit regulations it needs to be at least 12” in diameter and at least 2 ½” high. A heavy duty aluminum foil turkey roaster pan is acceptable and can be folded flat, but they fall apart quickly.
I looked and looked. They used to make car oil change pans from metal, but everything today is plastic. Hmmm, what’s this in Tractor Supply?
A “Spot Diner Time Stainless Steel Pet Dish, 5 quart, 12.15W x 4.25H. Like this.
http://www.petmountain.com/product/...5283/diner-time-stainless-steel-pet-dish.html
It is slightly tapered and – get this – the bottom of a 30L barrel fits it like a glove. No more bent and burned aluminum foil fire pan for me.