11
•Disconnect the yellow product water
tubing that runs from the Holding Tank to
the Manifold (see Fig. 1, page 1). Put
50 drops of bleach (this is ½ tsp. or
3 ml) into the tubing and reconnect it.
•Slowly open the Feed Water Saddle Valve.
When water begins dripping out of the
Dispensing Faucet, in the following order,
close the Faucet and then open the Holding
Tank Valve.
•Do not open the Faucet for at least 8 hours.
•Discard the first three full tanks of water
produced, they will contain chlorine.
•When the Faucet is first opened, expect air
and carbon fines (very fine black powder),
from the new Activated Carbon Post Filter
to be rinsed out. This is normal for the first
tank of water.
SECTION VI. TECHNICAL DATA
A. Water Quality
Water quality is normally measured with a special
meter that measures the water’s ability to conduct
electricity. The more dissolved solids in the water,
the higher the conductivity. The results are
usually reported in Parts per Million (ppm) or
Milligrams per Liter (mg/l) of Total Dissolved
Solids (TDS). (Although technically they are not
exactly equal, in most discussions ppm = mg/l.)
R.O. Membranes are rated by the amount of
dissolved solids that are rejected. This rating is a
ratio of the TDS in the feed water to the TDS in
the product water and is reported as Percent
Rejection. If the feed water contained 100 ppm of
TDS and the product water contained 10 ppm of
TDS, 90 ppm have been rejected and the reject
ratio is 90%.
Percent Rejection =
Feed TDS–Product TDS x 100%
Feed TDS
EXAMPLE: Feed water is 500 ppm TDS and the
product water is 75 ppm TDS
Percent Rejection = 500 – 75 x 100%
500
Percent Rejection = 0.85 x 100% or 85%
B. Water Quantity
Water quantity is termed Flux or Product Water
Rate and is measured as the amount of water
produced in one day. It is reported as Gallons per
Day (gpd) or Liters per Day (lpd).
The flow of water to drain is the Reject Water
Rate and is measured as Gallons per Day (gpd) or
as Milliliters per Minute (ml/min).
Milliliters per minute x 0.38 = gallons per day
EXAMPLE: The drain flow will fill a graduated
cylinder to the 105 ml mark in one minute.
105 ml/min. x 0.38 = 40 gpd
If the container available measures ounces, use
the
following conversion:
Ounces per minute x 11.2 = gallons per day
EXAMPLE: The product flow will fill 1¾ ounces
in two minutes.
1.75 oz. ÷ 2 min. = 0.875 oz./min.
0.875 oz./min. x 11.2 = 9.8 gpd
The Reject Ratio is the amount of water produced
compared to the amount of water flowing to drain.
Reject Ratio = Reject Rate_
Product Rate
EXAMPLE: The product rate is 10 gpd and the
reject rate is 40 gpd
Reject Ratio = 40 ÷ 10
Reject Ratio = 4 or 4–to–1
The Percent Recovery is another way to measure
the amount of water produced as compared to the
amount actually used.
% Recovery = Product Rate x 100%
Feed Rate
NOTE: The total flow or feed water rate into the
system is the sum of the product flow and the
drain flow.
EXAMPLE: The product water rate is 10 gpd and
the drain water rate is 40 gpd
Feed Rate = 10 gpd + 40 gpd = 50 gpd
% Recovery = 10 gpd x 100%
50 gpd
% Recovery = 0.20 x 100% or 20%