RO/DI clean to waste water

[magicwhistle]

So I see everywhere that the expected waste water to clean water ratio is supposed to be around 4:1 - 3:1.

I just set my unit up with a faucet adapter. Pressure gauge is reading 60 PSI and I’m only using cold water. I let it run for 50 minutes or so to flush everything out and am filling my tank right now.

However I did a bit of a test filling 2 cups and noticed that I’m getting better than 2:1 it’s pretty dang close to 1:1 actually. Is something odd or is this just good efficiency.

The TDS is still reading 0. Waste water TDS is at 250. The regular tap water is ~150.

 

[andrewey]

Which RODI unit do you have?

 

[magicwhistle]

https://www.maxwaterflow.com/5-Stag...everse-Osmosis-System-Float-Valve-_p_396.html
It’s this one however I just read through all the specs at the bottom of the page and it says waste ratio is 1:2 so looks like it’s fine. Was a bit worried for a bit there cause at the start I hooked up half of it backwards and pressure built up lol

 

[rmurken]

If you’re having warm weather where you are, a little bit higher temp out of the tap does wonders for the efficiency of your RO membrane (but obviously using hot water is a bad idea).

With 60 psi you might be able to get away with adding a second RO membrane in series. Better ratio, quicker production. Will consume DI resin quicker but not outrageously so.