Frequently Asked Question For Aquarium
RO unit
Reverse osmosis (RO) is a water purification process in which water is
forced through a semi-permeable membrane that removes 90-99% of tap
water impurities. The result is water that is free of minerals and other
contaminants.
Membrane type determines the amount of dissolved solids a unit is
capable of removing. For example, Cellulose Tri-Acetate (CTA) membranes
have a removal rate of 88-94%, Thin Film Composite (TFC) membranes
remove between 94-98% of dissolved solids, and Hi-S Membranes have
higher removal rates, between 97.5-99%, and are especially adept at
removing silicates.
More '
What is reverse
Osmosis ? '
Tap
water often contains impurities that can cause problems when added to an
aquarium. These include phosphate, nitrate, chlorine, and various heavy
metals. High levels of phosphate and nitrate fuel aggressive algae
growth, and copper, often present in tap water due to leaching from
pipes, is highly toxic to invertebrates. Because RO filters remove
practically all of these impurities, they are becoming more popular
among aquarists, particularly marine hobbyists.
Reverse osmosis and deionization (DI) perform the same task of removing
impurities from tap water. However, DI purifies water utilizing the
principle of ion exchange to remove impurities and replaces them with
pure water.
In most instances, an RO
unit serves as a well-rounded filtration method that removes the
majority of impurities; coupled with a post deionization filter, the
resulting water is 99.9% pure. Many RO units are available as a combined
RO/DI unit or are able to accommodate an
add-on DI unit
that simply attaches to your existing RO unit.
If your RO product water
is pure, your aquarium should have minimal algae growth, a steady pH
level, and low phosphate and nitrate levels. You can check the purity of
your RO product water using a conductivity meter,
TDS meter,
or by measuring the general hardness and alkalinity of the water with a
test kit. Purified water will have a general hardness of 0 GH and
alkalinity of 0 dKH. If your test values vary from those described
above, you may need to replace cartridges and/or the RO membrane.
It's not likely that you received a defective unit. But there are a few
factors that effect the output of reverse osmosis units. These factors
include; the source water pressure, temperature, and the amount of total
dissolved solids within the source water.
The ideal operating pressure for
a RO (reverse osmosis) unit is 65 psi (pounds per square inch). An
operating pressure of 45 psi will reduce the output of a unit by 50%.
There are pressure
gauges available to monitor the operating pressure of the system. If
the operating pressure is too low, an RO pressure boosting pump can be
added to increase the operating pressure to the ideal range. (click here
for more information about our SuperPump).
The temperature of the source
water should ideally be in the 70° to 77°F range for optimal performance.
A temperature of 50°F, or lower, will reduce the output of the unit by 50%
or more. Either hot or a mix of hot/cold tap water should never be used
for the source water due to the minerals that are added to the water from
most water heaters.
Finally, the amount of total
dissolved solids in the source water can reduce the amount of water
produced by a RO unit. The PurePro units are rated to treat water with a
dissolved solid amount of 500 ppm or less. If your source water contains
a higher concentration, it would be wise to install a mechanical
pre-filter in line prior to the unit. These filters are available at most
hardware stores. Because of the requirements of reverse osmosis units, it
is wise to purchase a unit that is rated above the gallons per day that
your needs require.
|
Q.
Is there any way I can check the
purity of the water my reverse osmosis system is producing? Also, how
often do I have to change the membrane?
|
Reverse osmosis (RO) systems remove most of the
impurities (heavy metals, minerals, nitrates, phosphates, and so on) in
tap water, giving you pure, healthy water for your aquarium. If your RO
product water is pure, your aquarium should have minimal algae growth, a
steady pH level, and low phosphate and nitrate levels. If these
conditions change, check your RO product water purity using one of the
following methods:
-
Use a conductivity meter (TDS
meter), which will accurately measure the amount of impurities in
the RO product water. Whereas regular tap water will have a reading in
the range of 300-500, purified water should be in the range of 5-25.
-
Measure the general hardness,
alkalinity, and pH of the water with a test kit. Purified water will
have a general hardness of 0 GH, alkalinity of 0 dKH, and a pH of 7.0.
If your test values vary from those described above, you may need to
replace the membrane.
The lifespan of the RO membrane depends upon the quality
of your source water. Under most conditions, an RO membrane will produce
about 25,000 gallons of purified water and last 2-3 years. However, high
concentrations of certain minerals such as calcium, iron, and magnesium
will shorten the lifespan of the membrane.
Back
to previous page
|
