Using rain water???

[Silver]

I was just wondering if I should use the water i collect from rain, what should I be testing from the rain water?

[ericatdallas]

You probably want to test the acidity of it. Also, the problem with collecting rain water is inconsistency of supply, storage, and collection.

[Northwoods Discus]

I think there are lots of things to consider. You would think it should be pure but it may collect contaminants from air pollution as it falls. It also would depend on what you are collecting it from.
I just bought an aging barrel and I wandered
into a section where they had all types of water collection accessories. Could get quite expensive. Then on DIY network I think it was This New House showed a clip where someone was collecting all the water they used for there home and filtered it to a point it was safe to drink.
Some of the worst algae blooms I had in our swimming pool were after a big rain. So maybe it collects things like algae spores on its way down also.
I think it should be soft water any way.

[Scott293]

I am also interested in using rain water. In a world going green these days, I have noticed quite a few people with drums under their downspouts collecting rain water from their roof for watering their grass. I have a Spanish tile roof which is like the clay pot material we use for our discus to lay eggs on. I don't see where my roofing material could cause a problem. If I use a solid black drum, the light wouldn't be growing algae in the drum. Then if I run a water line from the bottom of my drum to the basement with a filter and manual valve, it would be all gravity fed. I would also need an overflow for the drum outside going into my storm drain. It doesn't sound so hard to get set up and I could store multiple 55 gallon drums in the basement for winter. Food grade 55 gallon plastic drums are selling for as low as $8 each. Once it is set up, I would think the system would be virtually trouble free.

I'm just kicking ideas and thoughts out there. I don't have the testing equipment nor do I have enough knowledge about the water chemistry to know what I would be getting with rain water. I live in the city of Cincinnati Ohio. I would guess that the pollution in the air comes down with the rain. Maybe I should just take the bull by the horns and just do some testing for us all and see what I can find. I searched the forum and didn't find where anyone else had tried. If you have please let me know what you found.

[TURQ64]

So here's another angle on the 'why not to' side of the equation..I'm a Tallship sailor, been in Ohio a lot..All of the rot and dastardly things we face for repairs come from the rainwater you mentioned, nevermind the pollution..Many types of mold spores and nasty micro critters come down with the rain, rotting the hardwood my ship is made from. Freshwater rots boats, not saltwater. It's the cycle of degredation on the planet..Also why chemical treatments are done by the city to the water..If you 'collect' it, then you multiply all that stuff in a closed environment..Why trust your fish to the nasty stuff..The times when we are underway, and short on water, any that is collected is treated with clorine before use....like I said, just another angle..

[Scott293]

That's some pretty scary stuff there Captain. Not being a chemist, I wonder how I could test for such things? I have no idea what is in rain water. I do know that I can clean and wax my car, then it rains and I have water spots when it dries. So is this what comes down with the rain water, or is it dust that gathers on the droplets as they are evaporating? Your angle of how water harms the wood on your boat is interesting.