How long do I have to wait until I can drink the water? April 22, 2019 19:12 Follow Astrea has an “on-demand” filtering system. Just fill the bottle and sip the water through the straw. Related articles Can I use hot water? Can I use this filter to drink out of a stream/lake/outdoors? Does this filter purify saltwater? How do I know when the filter needs to be replaced? Do I need to do anything to it before it's ready to drink out of? Comments 0 comments Please sign in to leave a comment.