RODI question

[FDdragon]

I have a question regarding how one of these units work.

I have never setup or used one of these but my buddy recently set one up and was saying that he doesn't think its working correctly. He has a 4 stage unit.

He has his main supply coming from his water hose outside and after the unit does all the filtering....he produces 5 gallons of waste water and only 2 gallons of good filtered water.

Is this normal?

I have no idea how these units works so I figured I would ask. thanks all!

[antoneoh]

Whats the water pressure? If pressure about 40, you could be around 1 gal to 5 gal waste water. A booster pump can increase that ratio.

Should also check the TDI (total dissolved solids) with a TDI meter. Should be at 0.

[FDdragon]

ill ask him to check it this evening.

[davocean]

4-5g of waste per g is about normal unless you have a low waste unit, which are kind of expensive.
I'm at 60psi and get about 4g of waste.

[Frank H]

So where does this waste go? Down the drain?

[FDdragon]

So he is acgually using the unit to make clean water for some high end plants that he has. He is using the clean water now and has is using the "waste" water some of the lower grade plants to see if it has any effects....seems like even the dirty water is better than tap.

[Kris]

The waste water is concentrated tap water. The RO filter concentrates minerals on the waste side and lowers them (~90-95% rejection) on the "clean side". My tap is usually about 300 TDS going in and 30 coming out of the RO unit. I use DI resin filter to lower TDS to between zero and 7 before I change out resin.

I put waste water onto my lawn and fruit trees.