Ro system help

[aggiereefer12]

So I need some help/advice on my ro system.

It's a 100gpd system that I am lucky to get 25gpd out of. I have narrowed it down to psi and here are my readings when it dead ends into the pressure gauge

From source 60 psi
Inlet to ro 60 psi
Exit from dual sediment chambers (new cartridges) 60 psi
Exit from carbon (new cartridge ) 52 psi - probably should go to a larger pore carbon

When I let the sysrem run as normal for production my;
psi after sediment is 40 psi
Psi after carbon is 35 ish with fresh carbon block it usually is 40 psi

So my question is when the unit is running what's causing the 20 psi drop? Or where should I troubleshoot next?

 

[AZDesertRat]

What is your exact measured waste ratio? Sounds like you are sending too much down the drain and robbing the membrane of pressure. Also are you using cold water only and is the faucet or valve fully open? I run a 0.2 micron sediment filter and 0.5 micron carbon block for 18 months and still don't see a 2-3 psi drop between the tap and the membrane. You should not be seeing much of a drop if any with fresh sediment and carbon filters no matter the micron range.

 

[aggiereefer12]

I hadn't even thought of checking the waste to product ratio, but started a comparison a little bit ago so we shall see.... apparently in 10 min I produced about 4.5 gallons of waste water holy cow! And for all that I didn't get but a little under a quart. So not at all where the waste to product ratio should be. But is that due to low pressure or is something causing that bypass resulting in low pressure?

The second set of numbers is if I am to run the system for water production with the psi gauges in line vs having the water terminate at the psi gauge.

It used to get about 4- 5 gal an hour or roughly 100gpd

The membrane is probably close to 2 years but I can't be positive.

 

[AZDesertRat]

To measure the waste ratio use a measuring cup marked in either m/L or ounces and a clock or watch. Measure the waste flow for exactly one minute and write it down then do the same for the treated flow. The ratio should be about 4:1 or 4 times as much waste as treated in exactly one minute. Very easy and quick as long as you have an accurate measuring cup or graduated vessel.

 

[aggiereefer12]

I was getting rough 1:18. product:waste

 

[AZDesertRat]

That would be expressed as 18:1 and you need a new capillary tube flow restrictor. With the capillary tube you trim and adjust it to an exact 4:1 or whatever fits your water conditions.
You don't have a pressure tank on the system do you? Pressure/drinking water tanks make that ratio much higher and you waste a ton of water but can be improved with a small permeate pump which only works with a pressure tank.