I’ve been through several different types of water bottles and water filter systems over the years. The water bottle can be somewhat of a debate to those in the survival community. Some prefer stainless steel over plastic for the sole purpose of being able to boil your water. For a while I carried a 32oz stainless steel bottle for that purpose, but I honestly never found myself needing to boil my water. This would obviously be a benefit in more of a long term survival situation where a personal water filter may become compromised after too many uses.
Although I do still own a stainless steel water bottle I more often than not carry my trusty 32 ounce Nalgene water bottle with a nesting cup.
The Olicamp stainless steel nesting cup provides me with a means of boiling questionable water if I don’t want to use my water filter, melt snow to create drinkable water, or to just enjoy that hot cup of coffee in the field.
As for being able to filter questionable water I have settled on a simple, robust, easy to use personal water filter. The specific one I chose is the Sawyer Mini Squeeze Water Filter. This system contains no moving parts and is able to filter 100,000 gallons of water! Because of those two facts, this system will last you a very long time.