Pure/Waste Water Ratio and Flow Restrictor Q & A
 
1. What Is a Flow Restrictor?
A flow restrictor is a gadget designed to limit the amount of liquid or gas, such as water. 
It can allow users to reduce the amount of water needed.
 
2. What does the number on the flow restrictor represent?
It represents after reducing the flow amount, allowing greatest flowing amount of ML (0.000264 Gallons) per minute.
 
3. How to convert MLM (ml per min) to GPD (gallons per day)?
MLM * 60 (min per Hour) * 24 (Hours per day) * 0.000264172052 (US gallons per ml)
Common conversions:
 
MLM  GPD
185   70
250   95
350  133
450  171
600  228
800  304
1000 380
 
4. What is the best pure/waste water ratio of RO systems?
Most RO system are designed for 1 : 3.5 - 4.5 as standard. 
If the amount of waste water is too high that will cause a waste in water supply.
Also if it is too low that will cause a decrease of the RO membrane's available usage.
 
5.What is the pure/waste water ratio calculations?
For Example: for 100 GPD pure water output
Ratio  waste water(GPD)
1:2    200
1:2.5  250
1:3    300
1:3.5  350
1:4    400
1:4.5  450
1:5    500
1:6    600
 
6. What are the factors of pure/waste water ratio?
Factors could be, but not limited to the following: 
Incoming water pressure, 
Incoming valve dimensions, 
Water temperature, 
Incoming water TDS reading,  
Pure and Waste water TDS reading, 
Chemicals of water, 
RO system design, 
RO system using time..


7. How to choose the proper flow restrictor?
It should be based on ACTUALLY pure/waste water ratio, GPD and TDS reading. 
For example, if your system outputs too much waste water, you may change the a flow restrictor with lower number.
If it is too little waste water, the one with higher number could be better.


*** Important!!! ***
Please note, any other recommended number that just calculated on paper may NOT be reliable, because most calculations were for laboratory conditions only.
They may not be suitable for actually household conditions.
Our company recommend 450MLM for our RO system users by lots of our satisfied users.
If you have any other options, please contact us directly.