using soft water

[Marc]

I would expect that the test results for rain would vary a lot as rain can be influenced by the levels of pollution in the air.  Pollution would be more of a factor in the summer than in the winter time when cold clean artic air is prevalent.

[motoman]

Would the type of roof you have affect the readings too? I'm thinking that the logical way to collect a lot of rain water would be via your evestroughing so I wonder if a shingled roof would be worse than a tin roof? Just a though. My mom uses rain water to fill her pond in the summer (Goldfish in it) and she has a shingled roof. The fish seem perfectly fine and healthy so maybe its nothing to worry about but it may depend on the fish species your using the water for.

Motoman

[saltydog]

I once bought some fish from someone in the country who was selling because she was running out of water. Her well had low output & the dry summer meant that the rainwater that she relied on to fill her tanks was in very short supply.

[artw]

Remember David,  as Frank Zappa told us,  don't eat (test) the yellow snow

[manytanks]

A good point about the run-off from the asphalt-shingled roof. I wouldn't use it myself in winter or summer, and during the winter made a point of using only snow that was in the open field and not near the house.

With respect to using rainwater in the summer, I intend to rig some sort of tarp that will drain into a clean pail. The point about summer rain being more polluted is a good one, though. We live in the Almonte area and additional pollution seems not to be a problem (in winter) from the City of Ottawa, although it may be one from central and U.S. sources in summer.

//Manytanks