I believe the RO/DI is most efficient when operating at a 3:1 (waste water : clean water) ratio. However, the only way to really tell is to get a TDS (total dissolved solids) meter, and measure the TDS of your product (clean water). Generally, higher pressure is better. I operate mine at 85psi or so.
Pressure needed for RO/DI
- Thread starter RussReef
- Start date
How much pressure is needed for a RO/DI system to be efficient? I was thinking of using a sink in my house for my RO/DI system. I have always used the hose outside to hookup to my RO/DI when I need to make water. I know that the hose outside has a lot more pressure then the bathroom or kitchen sink does. Will the RO/DI system work less efficient using less pressure?
My RO/DI is a Typhoon III 5 Stage 100gpd.
My RO/DI is a Typhoon III 5 Stage 100gpd.
hi.
Both the outside hose and kitchen has the same pressure. There is a misconception that pressure is higher closer to the source, but this is not true. This misconception arose because of the slight restriction between the two outlets. When there is a flow restriction, there is an appearant loss in pressure when the flow rate is high enough. For statis pressure, the presure in a connected system is identical, unless the pressure is so low that atomspheric/hydrostatic pressure affects it. For dynamic pressure, the restriction will play a role, but for a 100gpd unit, this should not be an issue unless you have a really, really bad flow block in your faucet. Get a pressure meter and verify this for your self.
Both the outside hose and kitchen has the same pressure. There is a misconception that pressure is higher closer to the source, but this is not true. This misconception arose because of the slight restriction between the two outlets. When there is a flow restriction, there is an appearant loss in pressure when the flow rate is high enough. For statis pressure, the presure in a connected system is identical, unless the pressure is so low that atomspheric/hydrostatic pressure affects it. For dynamic pressure, the restriction will play a role, but for a 100gpd unit, this should not be an issue unless you have a really, really bad flow block in your faucet. Get a pressure meter and verify this for your self.
hi.
The membrane is pretty much identical among the OEMs of RO unit. If I remember correctly, almost all the membrane are made by Dow Chemicals. So the difference in pressure recommandation is not important for the same type of membrane. The rule of thumb is that the the higher the pressure, the better the output.
The membrane is pretty much identical among the OEMs of RO unit. If I remember correctly, almost all the membrane are made by Dow Chemicals. So the difference in pressure recommandation is not important for the same type of membrane. The rule of thumb is that the the higher the pressure, the better the output.
Interesting...
Anyway, mountainbiker, keep in mind that in addition to water pressure, other factors that greatly affect the output of RO are water temperature, condition of prefilter, and source water parameters. Two other factors are mislabeling of the membrane, and operator error like only turn on the RO for 2 hours a day, etc. How much brine did it made for for every 10 gal that it produces?
I have an ARS 50gpd system and with my sink presssure was about 38 to 40 psi i was getting about 25 gpd, i bought a boost pump ran the pressure up to 88 psi and i get almost 70 gpd! with a tds ranging from 0.0 to 1.0 i believe the 1.0 is because of the containters i am using i rinse them with tap water before i put in ro/di water. The boost pump is a good investment. AquaFx has them running around $159 before the 10% discount .The discount is for the month of Jan. If you are a member of reeflounge forum they will give you 20% off.
hi.
For some people, booster pump is really necessary. But for most people, I won't call it a good investiment. Depends on your water usage, it probably takes years to recoup the inital purchase, as well as the running cost (electricity). Just my 2 cents worth.
For some people, booster pump is really necessary. But for most people, I won't call it a good investiment. Depends on your water usage, it probably takes years to recoup the inital purchase, as well as the running cost (electricity). Just my 2 cents worth.
We just replaced our membrane and all cartridges last week. I run the waste water down the laundry drain, and never really paid a lot of attention, but measured the ratio tonite (at 42psi).
3.25 to 1 I am very pleased with this.
It is/was a ReefPure I got on Ebay...75gpd.
I know it slows down in the winter when the water is really cold, so far our winter has been quite mild.
3.25 to 1 I am very pleased with this.
It is/was a ReefPure I got on Ebay...75gpd. I know it slows down in the winter when the water is really cold, so far our winter has been quite mild.
Hi O P Ing: LOL good one. about recouping the cost of the boost pump. I have yet to recoup any cost in this hobby. The only real payback is an awesome looking tank you can cherish. My water pressure here is low and i can still get RO/DI water but at the rate of less than 24 gal a day. with the pump it goes up to almost 88 gals per day and tds of 0.0 to 1.0 with a 50gpd RO/DI set up. Well those gpd ratings are based on 65 psi i think.. The time saved is worth the cost. Plus i run it about maybe 4 hours tops a week. My fridge light sucks up more wattage LOL. Plus when i move from this location sooner or later I will already have a boost pump avail if I ever need one at my new location. Your two cents worth is welcome anytime in this hobby i need all the donations i can get
SPC: I stand corrected it should read 88 psi with an output of 70 gals gpd on a 50gpd system. I did not remove any restrictors or anything from the system. It is an Aquatic Reef system 4 stage 50 gpd RO/DI system. I know quantiy and quality of output water is a function of the membrane and the input water pressure along with input water temp. Most systems are rated for 65 psi. I presume that by running close to 90psi I am forcing the system to its theoretical limits. Whether this shortens the life of the membrane and filters only time and close monitoring will tell. I'll let yall know as soon as i do. Would be nice if something as simple as increasing input pressure to get more output water rather then having to upgrade the system by buying higher gpd rated membrane.
My pressure in the house is around 90. I can get 72 gallons a day out of my 50gpd unit. The 50gpd rating must be at a lower pressure. As for the life of the membrane at the higher pressure, I asked the guy I ordered it from and he said it probably would shorten the life, but not the quality of the water up to that point.
Regards, Eric
Regards, Eric
King Jason , I agree with SPC 50 psi is very good. I only needed a boost pump because my pressure was running as low as 30 psi The pump just happen to give me a very LARGE pressure boost which worked out to my advantage. If you are looking for more output product you might want to use a boost pump. But if 50 psi is meeting your RO/DI water requirements dont bother with the pump. Remember: if it aint broke don't fix it.
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