Every situation is different and there are different needs, so I don't want to say that our house is the answer, it just might give you some ideas for what you might want to do.
The bioshelter was built in 1985, so the system has been working for all of these years. Well, the first 10 years the builder did a lot of adjustments and modifications.
The water is caught on the roof with 2 drains that gravity flow down into the solarium which is a constructed wetlands. It's gravity feed mostly into the 5,000 gal water cistern. We DO run it through a UV light before it gets pumped into the cistern. We also have a carbon and sediment filter it runs through on the way to the faucets.