filling a tank with rain water?

With all the smog around, I don't think rain is a very good source for aquarium water. Even if it's a clean cloud, by the time the droplets get to the ground they intercept a lot of the crud and pollution in the air. I'm not an expert though, I just think it's logical.

I see a rainforest as a gigantic biological filter, so I imagine the rain there, even if it's tainted with pollution, will get purified rather quickly.

I think we ought to stick with the tried and true method of treated tap water for the fishies.

It really depends on what area you live in whether rainwater is suitable for your tank (or human consumption for that matter...)

Large metropolitan areas, or areas with a lot of traffic flow, I would advise against it, but someone who lives way out in the backcountry could certainly use rainwater without any problems. Best way to know if it's acid rain is to test the ph... it's acidic after all. If you get a really peculiar reading, don't use it.

My grandmother still collects rain in a barrel to water her houseplants and wash her dishes with to this very day.

I would suggest in any event that you let rainwater age in the barrel for a few days, just to make sure any harmful stuff in the cloud has a chance to settle and/or gas off, depending upon the impurities present in your little neck of the woods, and filtration through a carbon filter before introduction to your tank, just to be sure, but then, I'm really anal about water quality.

I think there's a couple topics on wetman's site (can't remember the link name, sorry), regarding using rainwater.

Hey Hans,

Check out this article on rainwater from aquasource...

http://www.aaquaria.com/aquasource/rainwater.shtml

well, a local guy I'm buying some cichlids from collects rainwater for his checker barb tank and didn't mention any difficulties or problems. He said the checker barbs are extremely picky so this is why he's using the water. I'm sure location makes a large difference in water quality. my only concern with using it is how to efficiently collect it without adding pollution to it. My grandfather collects it off his roof for watering his plants but I don't want roofing chemicals in my water. Kyle

Yes, location is the main point here. Acid rain is primarily caused by SO2, usually only found near industries and heavy auto traffic, for example in mostly-urban regions like Germany (where Hans is from). On the other hand, in generally rural Oklahama, USA (where snakeskinner is from) or Tennessee (me), there is not much SO2 in the air and consequently no acid rain. So it probably won't work for you , Hans.

Wow, I don't know what part of Tennessee you're from, but the Smokies have real issues with acid rain due to all the tourism traffic