Please, Help on RO/DI Questions: Pressure, Ext...

what type of Ro/Di unit are you using? i can give you a diagram of how mine is setup if you need.

 

Hot water comes from the water heater with vast increases in all dissolved elements (rust, evaporation etc). That will decrease the life of all your elements and could adversely effect the product RO water from the get go. I would try to use cold water.- Paul

 

Hey, bulk reef supply sells a float valve kit for their systems, I think thats what you said you have. If you put a float valve on you also need another valve that keeps back pressure off the membrane, which would lead to damage to the membrane. Some of BRS units come with this valve already, but some do not. They have the kit available on their website and its a reasonable price.

Hope that helps,
Jake

 

yep, without that stop valve the pressure will actually break your filtration unit overtime and wear down your float valve as its not rated to handle 70psi

 

Dow Filmtec advertises their RO membranes to produce their rated output at 50 psi and 77 degrees F water temperature.
Most of us do not have 77 degree water so pressures higher than 50 psi are recommended, up to about 90 psi is perfect. Too little pressure and your product or treated water production goes down and your membrane does not get sufficient flushing which can lead to premature failuyre due to fouling.

Float valves and float switches require an autoshutoff valve (ASOV) which shuts off both the product or (treated) and concentrate (waste)flows. No need to shut of the incoming water, the ASOV shuts off the outgoing treated and waste water and maintains the unit under pressure so no bacteria can enter.

Hot water will melt a membrane faster than you can read this post. They cannot take anything over 113 degrees and its best to stick with cold water only. If production is low add a booster pump, DO NOT try to blend hot andcold water. Remember being in the shower and someone flushes the toilet or starts the clothes washer? You got scalded and the same thing happens to a membrane. You will also find cold water gives better treatment (lower TDS) than warm water and wil make DI resin last longer.