Thinking of making a rainwater automatic water system.for my chickens. Anyone using rain water for chickens
Good idea! Assuming, you're collecting from a roof run-off, be sure the roof is wood, metal or ceramic tile. Not typical composite materials. The composite materials will leach some toxic petrochemicals into the water. And if wood, not cedar, cedar has some toxic oils in it.
Over time, I think, some of the rocky covering washes down and would worry about wash of the tar/asphalt compounds.
I have a rain barrel I set up to water my cold frame plants a couple of years ago. I used a pickle barrel and attached a hose spout. I don't have a faucet down at the coop/run, so I have to run a 100ft hose from the house. I sometimes use the water from the barrel to top off the chicken's water if I am in a hurry. The funny thing is this barrel keeps water reasonably cool in the summer and hardly ever freezes enough to be a problem in winter. I drain it and clean it occasionally and it also does not get green and nasty like you would expect. I have been thinking of trying to set up an automatic water system using it.
My wife did an organic gardening course a couple years ago, run by science-y type folks. They said it had been shown that the tar/asphalt of such roofs does wash off and end up in the run-off water. Makes sense. I wouldn't use it if you plan to eat the eggs, organs or the meat of your chickens.
The fact that some washes off doesn't mean that it's dangerous. If you're worried about it, make a diverter - so the first couple of minutes of rainwater gets discarded before starting to fill your cistern.
Compared to the run off water in puddles that chicken drinks from roof water is pristine, even if off a asphalt roof... I wouldn't hesitate using it all for livestock, but bewares it's not 'clean' birds flying over and critters running around the roof will leave behind #1 and #2 deposits, as well as whatever else lands on the roof and starts decaying or rotting will all contribute to water contamination as will the minute traces of whatever the roof it made of...
It also doesn't mean it's safe. And since tar and asphalt are known carcinogens, why bother? Once in a while might be fine and the liver could deal with it, but day in and day out, it could add up. And effect the chicken's health, their eggs and/or meat. Maybe it wouldn't be enough to matter to some folks. I'd rather not have it in my food if I could help it. Chickens don't really require that much water.