RO+2DI REVERSE OSMOSIS Question

[rmleal]

http://cgi.ebay.com/AQUARIUM-2-110G...hZ002QQcategoryZ20756QQtcZphotoQQcmdZViewItem

I got this RO+DI unit and started it for the first time yesturday at around noon time. at around maybe 8PM i only had like 7-10G od RO+DI water. This is my first RO unit and it seems to go slow or is it just me?? it drains at a good rate but trickles the RO water.... Im i doing anything wrong? the input is 98ppm and comes out 0ppm so i know im good in that end.

 

[Reef55]

The rate at which RO water is made is highly dependant on both the water pressure at the input to the RO membrane, and the temperature of the water. Low pressure combined with cold water (less than 80 degrees) will mean slow output.

 

[rmleal]

its real cold water and from what i was told from my inlaw the water pressure it good....

 

[smcnally]

That is the same unit I have. It should be putting out close to a gallon every 15 minutes. If it isn't, your water pressure may be a bit low. Your water pressure may seem "good" to your in law, but they may not know what "good" is when it comes to what an RODI requires. Real cold water will actually slow down the output some as well.

 

[Rays]

And.... your waste water is around 3-4 gallons to 1 gal processed water.

 

[rmleal]

OK it seems that i need a pressure pump because it was something like40+G bad water for the only 8-10G i got.. Where can i get a pump?

 

[DLCanuck]

On the RO/DI the best pressure for the unit is 60psi at 65F to 72F, in most house pressure is somewhere 40psi to 80psi. When the temperature is less then 50F the water is heavier as it gets colder. If the unit rate 90gpd it might be doing 45gpd cause the water temp. The flow restrictor may need to change to compensate the lost on GPD. But then in near summer time you need to change the flow restrictor. Because the water temp will go up. If you have lest pressure then 40psi you will need a booster pump or greater then 80psi you will need a regulator. To test it out the GPD here what you got to do or go to this wed site http://www.spectrapure.com/manuals/DELUXE_CSPDI_SYSTEM.pdf


Membrane Output Calculation Example
What is the expected GPD from a 75 GPD System at 40 psi pressure and 60?F
water temperature?
PCF = 40 ? 60 = 0.666
TCF = 0.754 (from Table 1)
Expected GPD = 75 ? 0.666 ? 0.754 = 37.7 GPD ? 15%
37.7 GPD would be the Actual Production Rate

Membrane Output Calculation
Membranes produce the rated gallons per day (GPD) at 60 psi (4.1 bars) operating
pressure, 77?F (25?C) operating temperature and 500 ppm total dissolved
solids.
Membrane output gallons per day (GPD) depends on operating pressure, water
temperature and the ppm TDS in the feed water.
Expected GPD = Rated GPD ? PCF ? TCF
PCF is the pressure correction factor
TCF is the temperature correction factor
Calculation of Pressure Correction Factor (PCF): The output (GPD) from
the membrane is directly proportional to the applied pressure.
Note: The membrane is rated to produce the rated GPD at 60 psi. For any pressure
other than 60 psi the output GPD is multipled by the PCF.
PCF = Line Pressure (in psi) ? 60
Calculation of Temperature Correction Factor (TCF): The output (GPD)
also decreases with decrease in temperature. This is because water viscosity
increases with decrease in water temperature.
Temperature Correction Factor Table (TCF)
?F /?C TCF ?F \?C TCF ?F \?C TCF
41.0 /5 0.521 59.0 /15 0.730 77.0 /25 1.000
42.8 /6 0.540 60.8 /16 0.754 78.8 /26 1.031
44.6 /7 0.560 62.6 /17 0.779 80.6 /27 1.063
46.4 /8 0.578 64.4 /18 0.804 82.4 /28 1.094
48.2 /9 0.598 66.2 /19 0.830 84.2 /29 1.127
50.0 /10 0.620 68.0 /20 0.857 86.0 /30 1.161
51.8 /11 0.640 69.8 /21 0.884 87.8 /31 1.196
53.6 /12 0.661 71.6 /22 0.912 89.6 /32 1.232
55.4 /13 0.684 73.4 /23 0.941 91.4 /33 1.267
57.2/14 0.707 75.2 /24 0.970 93.2 /34 1.304

 

[Reef55]

OK it seems that i need a pressure pump because it was something like40+G bad water for the only 8-10G i got.. Where can i get a pump?

That is about the right ratio, 1 part made to 4 parts waste. You only need a booster pump if your pressure is under 40.

 

[rmleal]

Ok so my pressure is ok and i think maybe also the 1/4 tubes are not cut i used the long tubes they gave me and didnt cut it down will that casue it too?

 

[Reef55]

long 1/4" lines should not have any effect on pressure (unless it is like 1000 feet long or something).

Only way to check pressure is to put a pressure meter just before the membrane.

 

[delta]

IME Water temperautre and pressure will affect production. If your using a saddle valve they clog very easy they also reduce pressure somewhat anyway.. Close the valve an open the faucet to your sink to try and clear the hole. Then reopen the valve, it may help it may not.
The water temp is easy to fix, take all that excess line you are using and coil it in a bucket throw a heater in and fill it with water. Then set the heater to 78degrees. This alone will definately increase production and quality. If that is not enough invest in a pressure pump. Money well spent once you see how fast your unit can really produce.