PL-5000 RO System

[bisonfan]

We own a PL-5000 RO system in our lab which has been running for some time. Before starting a new project, we checked the purity of water from the RO system in the analytical lab to find that the water quality is not as good as we were expecting from the system. The total organic carbon was found to be 0.93 mg/l while the conductance was measured to be 150 uhmos/cm (6.67 MOhm-cm). I was wondering if that is the limiting factor of the RO system or the system is not performing as it should ideally be. Can you provide me with a data sheet that can elaborate the capabilities of the system that we are using?

[waterfilters]

Can you translate your findings to TDS in ppm? The RO system is capable, with a new membrane, of removing 95+% of TDS. Typically membranes are replaced when the go below 80% removal rates. You may want to consider changing your membrane more frequently than that.

A real solution would be to run the RO water into a small pump, and feed it through a standard cartridge style filter system with a DI cartridge to bring the TDS and conductivity down to the levels you desire.

Here are the housing and cartridge I would recommend: 20 Inch Big Blue Whole House Water Filter Housing #20 from Ametek, USFilter, and Pentek and BBF1-20MB deionization water filters and Pentek BBF120MB filter cartridge 155281 for deionized water

Thank you,
WaterFilters.NET

[bisonfan]

Thank you for the response and the suggestions. We got a couple of water samples tested by the local Culligan lab to find that the water being supplied to the RO system was 155 TDS in mg/l while the output from the RO system was 23 TDS in mg/l. The results from the analytical lab showed that the total organic carbon from the RO water was 0.93 mg/l or ppm. Does the result indicate that the membrane has to be changed?

[waterfilters]

According to those #'s the membrane is working @ about 85% efficiency. This would be 95+% with a new membrane. The TDS on the outlet side of the RO could be down as low as 5-7ppm TDS. Then to take the TDS lower (and simultaneously reduce conductivity) and produce 16 megohm water commonly used in laboratory situations, you could run the water into a small pump like this: GE Merlin Booster Pump 1240632 and Aquatec 5501-IVN2-V77DUL Smart Pump and into a cartridge housing like this: Whole House Water Filter Housings 150166, 150069, 150071 from Pentek, USFilter, and Ametek with a mixed bed DI cartridge like this: Pentek PCF1-20MB deionization filter and Ametek PCF120MB D.I. Resin Deionization water filter cartridges 155274

Just FYI.

Thank you,
WaterFilters.NET