At a 4:1 waste ratio it costs me .04 cents per gallon to make my RO/DI water and that includes the sewage costs and water costs. Our sewage costs are based on our water usage so no way around that unless I have a dedicated meter put in for lawn care which is a huge hassle.
I'm curious though, how are you guys using it in your washing machines? Just stick the waste line and fill it up, how are you bypassing the part where the washer tries to then fill itself up with water? Can't say I've ever tried washing clothes by bypassing the water fill up stage of the washing machine![]()
If you calculated your filtered water costs 0.04cents per gallon (which means for one gallon filtered, you used 5 gallons tap), then 100 gallons waste water you saved costs 0.8 cents, not even 1 cent.
I'm not a scientist, but I work in a lab with lots of biologists and chemists. I ask them stuff all the time. Most of them agree (separately) that between the two, DI is more important because some bad ions are smaller than the RO membrane can filter out. Also, the water that comes out of any RO unit - even the multi-bazillion dollar ones we have at the lab - is NOT 100% pure water and nothing else. I would never consider an RO unit because of all the waste. I use DI only, which has no waste. There's enough waste to deal with after a water change - I don't want to add to it.
Great attitude! :thumbdown+1 water is so cheap. I waste mine all day long!
It's not exactly the same, water is a renewable resource, crude oil is not.