Rain Water
 

Hi Team,
I have been capturing rain water from my rooftop gutter down spout into a 90 gallon water reservoir. I typically wait until all the pollen and other debris has been washed away and then begin the capture.
It seems to be very good quality water. It is typically measuring 0-1 PPM on my Hanna meter. It is much purer than my city tap of 70 PPM. But I question the chemical content which may not be measureable in PPM. I have a typical shingled roof in GA. My home is about 3 years old so I don’t worry about glue too much. But what other harmful chemicals can be in the water and what is the best method to find out?
I read online that water captured from rooftops with shingles such as mine is only suitable for irrigation not drinking. I feel somewhat that if I can’t drink it then it is not good enough for my hydro plants. But then plants on farms grow under rain water so I am confused.

Thanks,
StrangGuy

The only way I know of is to have samples sent to a lab.

Well plants can and do grow using all sorts of water, they will even grow using sewer water, that doesn't mean just because they are growing, they are healthy. And plants have been growing with rain water all over the world for millions of years. Although rainwater quality will vary from place to place, it's generally a good source of water.

Rain water is just fine to drink as it falls out of the sky (except acid rain), the contaminants come from how it's collected and stored, even if it's dripping down through the trees. Everyone has there own ways and beliefs, that where the biggest difference in rainwater quality is. But even in a regularly cleaned system I would still filter it before I drink it myself. I would also filter it before use in my hydroponic systems. It would be real impractical to filter thousands of gallons to water to your yard, but it's not so impractical to filter 20-30 gallons for your hydroponic system. It really depends on how you feel about water quality for your hydroponic plants.

I don't filter mine. Maybe I should, but I doubt I will. I just use it as is from the barrel which is from my roof. Using the logic of "if I can't drink it I don't want to give it to my plants" isn't necessarily a good way to approach it. I use worm casting tea on my garden. The plants seem to thrive on it. No way I'd drink it. I wouldn't drink hydroponic nutrient solution either, but my hydro plants would die or at least perform very poorly without it.

Run off from roofs can have some harmful chemicals from not only the roof, but from the deposits from fossil fuel exhausts. Plus, it may also have other pollutants depending on how close to industry you are and what industries are near you. I don't know in what concentrations, so I just don't risk it. I also would filter prior to drinking it just for safety. There are likely some bacterial contributions from any debris on the roof or in the gutters. I'm sure some from bird poop.

You can often have your water tested by the treatment facility or by some universities. Try calling your local extension to see if they can recommend anyone or point you in the right direction. Some of the most common pollutants are actually not bad for plants (nitrates, for example).

Just thought I would post a link in case anyone was not sure what was meant by "your local extension"

Cooperative Extension System Offices

Like Joe mentioned, it's a great way to get good information (especially local) from a creditable source, and should at least be able to point you in the right direction.

I had made a decision to install rainwater at my home to store rainwater. With the decision of to install rainwater tanks i also want to install rainwater filters to make water clean for drinking and cooking purpose.

rainwater filters