UV filtration for catchment water

[randomq]

MarkP, question about your gravity fed setup:

Is your filtered water tote vented to allow water to enter without pressure buildup? If so, is the vent elevated above the level of water in the catchment tank, to prevent overflow?

I'm considering a similar setup. Probably with some basic filtration in front of the Sawyer. And any issues with using chlorine? Still need to kill the viruses...