Too much for my RODI

Thanks for reading here. I've had my RODI for almost 2 years, flow has been fine, and the color changing resin has started to brown. In the last 3 weeks I've noticed (and really just started) to see my flow rate getting to be about 5g/ hour. Realizing this was wayyy too much for a 50gpd membrane, I went straight out and bought a new membrane (50gpd), and new resin. My 2 other chambers appear clean, the charcoal filter only showing a slight pencil line of red, and the other completely white. My issue is, after replacing everything, I'm running my first 10g of dump water, and it produced 5g in 73 minutes. Just over an hour. If it should only make 50pgd, why am I producing almost twice as much. I also added a new check valve in place of my flow restrictor. Check valve is closed. Thanks for any input. I'm stumped.

 

My second 5g came out in 74 minutes. Pretty well on par with the first. It's possible I got a 100gpd by mistake, but we were all pretty certain it was a 50gpd. I guess my biggest consern is, what else would cause my 50gpd to be so off?

 

Whats the pressure that your system is running?

 

What is your water pressure and water temperature? What is your exact measured waste ratio using a measuring cup and watch or clock for exactly one minute?
What is your tap water TDS, RO only TDS and final RO/DI TDS?

Tell me what you mean by "check valve in place of the flow restrictor? Do you mean you are not wasting anything? I certainly hope not as membranes must be continously flushed to stay clean when in operation.

 

My pressure gauge broke, but I believe for city water my pressure is indeed too high. I made some calls today and one is in the mail. I "assumed" all city water was at adequate pressure. Really didn't think it could be too much.

I'll check what you're asking for after work today. I think you both nailed it with the water pressure.

As for my "check valve", I think a better name is flow restrictor valve?
I sometimes go all crazy and put custom names on items. It's dangerous I know. But this item is easier than a flow restrictor when flushing my membrane.

I'll check my water pressure and update.

 

More pressure is actually better, 40 psi is bare minimum, 60-80 is much better and membranes love 90-100+ psi as long as the housings and fittings are quality pieces.

When you are using the system, do you make sure the waste is flowing all the time. That valve you pictured is just part of a "flush kit". It should have a bypass around it to work correctly so you get 4:1 waste ratio in normal operation and you can open it up to flush which really doesn't accomplish much but give you a warm fuzzy feeling. You would be better off with a properly trimmed capillary tube flow restrictor and forget the valve.

Your water pressure and water temperature will determine how much flow you get. Also if you are not running the recommended 4:1 waste ratio the pressure wil be higher too since it is not being used to flush the membrane as it should be doing.