Rain water health

[Dollythehun]

It will be nice if we could stay on topic here.

I catch rainwater in my rain barrel. The sediment falls to the bottom. However, yesterday I noticed that my rain water is yellowish. We have a fairly flat roof, a rubber roof. I'm sure there's a bird poop up there, I know there's leaf debris. And God knows what else, maybe road to dust.

So my question is while rainwater is good, what's in the rainwater? One of our members taught me to filter it through a coffee filter, with a gold coffee filter underneath that. So there's no debris in it. But I got to wondering what else might be in there? Thoughts on this topic? Bleach?

One might suppose that in the wild all of the above mentioned things are present.