Rainwater catchment for duck's drinking and swimming water

I am currently designing a small backyard system for three layer ducks.
I would like to use rain water catchment for their drinking and bathing water.
After reading Rob Avis's recent book on water catchment I am confident it can be done
to manage for best water quality. Plus ducks are quite hardy aren't they? Body temps of
107 F.
Is there any reason to be concerned about using rainwater for their drinking?

Other notes:
I am in a wet region and tank should turnover 1x-1.5x per week.
In winter they will be getting indoor water anyway.

Thank you for any thoughts.

Also, how important is it to have a small outdoor protected area (apart from the run)
where they can sleep outside if they want to?

Nick

Yes rain water should be better for them than city water slightly better than well water.  It could possibly reduce your work load. Ducks cleans their bill in the water which adds a lot of organic material to the water each day. If they swim in it they also dedicate in it.  The smaller the volume the more frequently it needs to be emptied to remove the valuable accumulation of fertilizer. Having a drain that allows you to directly transfer it to your plants would be very helpful. Alternatively having a rain garden that they can feed in naturally is an option if you have the space. If there is a bush that gives sun shade and arial predictor protection they will rest under it and sleep there if they are not shut in at night. If there is a night light that attract insects they will stay there and eat falling insects all night. Wa a huge saving on our feed costs.

What is the surface of the rain catcher made of? Urban roofs have sediment runoff.

Hans Quistorff wrote:Yes rain water should be better for them than city water slightly better than well water.

Maybe. There are a lot of factors - like location. In some areas, the rain can be acidic, and depending on the roofing materials, the water might need to go through some filtration. Also, not all well water is the same. I've had well water that was distinctly nasty, some -maybe most - that was'meh', and now, I'm blessed with some of the sweetest, cleanest well water I've ever had.

I have a small, one barrel system for my chickens.
Obviously they use a fraction of the water,  but I  think I have some pertinent information to share.
I collect from a single 6x7 foot tarp, no roof collection.
I use a 5 gallon bucket set into the top of the barrel as a filter.
It's full of construction grade sand, and the tarp directs water into it.
The water stays sweet and clean smelling.

I'm guessing you will be using a head dunking stystem with a float valve?
Those systems seem like the "driest" you can go with ducks without being cruel.

The film Don’t Flush Your Freedom Away has an example of a filter setup for drinking water. It is kind of extreme for a desert environment for water conservation. This setup has four filters for sediment filtering.