Rainwater collection to RODI a good idea?

Tennyson · Jul 8, 2022

Hey everyone,
Recently had a plan to save on the water bill by collecting rainwater to feed a RODI filtration system inside. Just wondering how practical this would be? How many gallons would I need to make it worth it? Can I also save the waste water from the RODI filtration process and reuse it for distilled water?

I'm guessing you could use a pump rated for 50 psi and plumb it to the collection tanks like the picture I found below. Would you use copper pipes too? Trying to figure out how easy this would be to DIY, I don't have much experience with gutters and wouldn't want the house to look overwhelming with PVC, as much as I love using it to plumb my tanks together. Any ideas welcome.

My RODI system is an Air Water Ice Typhoon III for Reverse osmosis Deionized water.

toomanymatts · Jul 8, 2022

You are going to have to filter all the junk off from your roof and everything else. It would seem that you are going to blow through filters doing this...

mdb_talon · Jul 8, 2022

I dont think this is practical in terms of cost effectiveness unless your water costs are astronomical or you can get that equipment really cheap....and you get a lot of rain. From an environmental impact perspective i even still doubt it makes sense if you are factoring in the environmental impact of producing/transporting/etc those barrels and the other equipment you need.

On a localized level if your are in someplace like southern california maybe it could make sense if it werent for the fact it almost never rains there lol.

I do think it would work though. I think a big key would be adequate mechanical prefilters to get the "big stuff" out that could be rinsed and reused.

Tennyson said:
Can I also save the waste water from the RODI filtration process and reuse it for distilled water?

The waste water would not be distilled water because that is not what distilled water is, but probably more to the point the wastewater is just similar to the quality of the sourcewater but with concentrated levels of impurities/minerals/etc.