Diatomaceous
Earth (D.E.)
The D.E. filter is the most efficient type of pool filter
on the market. It can trap particles down to 3 - 5 microns.
As with sand filters, the pressure gauge indicates a need
for backwashing when it reads 8 - 10 lbs. higher than
its clean reading. After backwashing, a new application
of D.E. filter powder is added to the filter by pouring
into the skimmer. In order to thoroughly clean D.E. filter
grids the filter must be broken down annually.
A D.E. filter requires that the you add D.E. powder
to coat the filter grids inside the filter tank. The
powder, which is added at your skimmer, dissolves in
the pipe on its way to the filter tank. When it reaches
the grids, the powder stops, coating the grid. The water
continues to pass through, first through the powder,
then the fabric covered grid. As the water passes through
the D.E. and enters the grid it leaves the dirt trapped
in the D.E. powder "cake" or coating.
The D.E. powder is what filters your pool water in a
D.E. filter. Do not operate your pump without having
the D.E. powder coating the grids, or you will see your
pressure rise very quickly, and if left in this manner
the grids could become damaged. As the pressure gauge
on a D.E. filter increases, flow rate decreases. Eventually
the flow rate cause the water quality to suffer. backwashing
the filter will remove the D.E. that is clogged up with
the dirt. After backwashing thoroughly, add new D.E.
powder to the filter through the skimmer. If using biguanides
(Soft Swim or Baquacil) you will need twice annual,
very thorough cleaning to prevent it from gumming up.
All D.E. filters should have this done at least once
per year. Thorough cleaning is accomplished by turning
the pump off and draining the filter. Remove the tank
top half, and remove the grid assembly. Hose the grid
assembly thoroughly. If you want to take it a step further,
after hosing, soak the assembly in a trash can filled
with water and a filter cleaning product. Rinse thoroughly
before reinstalling grids.
When backwashing a D.E. filter, do the backwashing process
several times. That is, backwash until water runs clear,
move the multiport valve to FILTER and run it on filter
for a 5 - 10 seconds, and backwash again until it runs
clear. Repeat this about 2 - 4 times. Remember to always
shut off the pump before turning your multiport valve
or your push-pull valve. Each time you go through the
cycle of filter/ backwash/ filter, you will get more
dirt/ D.E. out of the filter, giving you a better, more
thorough backwash.
Also important in ensuring an effective backwashing
is making sure skimmer baskets and pump baskets are
clean to allow for full flow entering the filter.
|
How
do I Backwash my DE Filter?
When the pressure gauge is reading
8 - 10 lbs above the clean, starting pressure, it
is time to backwash the filter. This process involves
turning a valve so that the water will flow through
the filter backwards, flushing out the dirt. Sand
filters can have either a push-pull valve (also
known as slide valves) or a multiport valve. The
multiport valve has multi-ports on the valve, usually
6 positions:
1. FILTER: Keep it here 99%, except
when backwashing, rinsing or wasting
2. RINSE: Use this setting for
20 seconds after backwashing to rinse tank
3. RECIRCULATE: Use this if the
filter's broken; at least you're circulating.
4. BACKWASH: Use this setting to
reverse the flow in the filter and send water out
of the waste line. Make sure valves are open or
hoses rolled out
5. CLOSED: Put here to close off
flow from the pool, usually to work on the equipment.
Do not operate pump with valve in closed position
6. WASTE/ DRAIN: Another filter
bypass setting, but this one sends the water out
of the waste pipe (hose), instead of returning it
to the pool. Used to lower pool water level or to
vacuum to waste
|
To backwash a D.E. filter with a
multiport valve
·
Shut off pump motor
· Press down on
valve handle, rotate valve from FILTER to BACKWASH
position
· Roll out any backwash hose
or open any waste line valves
· Open
air bleeder assembly on filter, and turn pump on.
· Watch pressure gauge for backpressure
and hose for kinks. Be prepared to shut off pump
quickly
· After hose fills with water,
run for 2 - 3 minutes or until water runs clear
· Shut off pump motor and move multiport
valve handle to RINSE position. Run on rinse for
5 - 10 seconds. Shut off pump again, and move handle
back to BACKWASH. Turn on pump again until water
runs clear. Continue in this fashion 3 - 4 times,
alternating between Backwash & Rinse, to ensure
a thorough backwash.
· Shut off pump
motor and move multiport valve handle to FILTER
position
· Turn pump back on and note
lower pressure. Roll up backwash hose
·
Add 1 lb D.E. powder per 10 sq ft of filter area.
Look on filter tank
|
|
To
Backwash a DE filter with a slide valve:
· Shut off pump motor, roll out backwash
hose (if you have it)
· Twist to unlock
plunger T-handle, pull/ twist plunger upwards 2
- 3"
· Open air bleeder assembly
on filter, and turn pump on
· Watch
pressure gauge for backpressure (+ 40 PSI) and hose
for kinks. Be prepared to shut off pump quickly.
· After hose fills with water, run
for 1 - 2 minutes or until water runs clear. Shut
off and push handle back down. Turn pump on and
run in filter position for 15 seconds and then shut
pump off and backwash again for 1 min. Filter again
for 15 seconds and another 30 second backwash.
· Shut off pump motor and push T-handle back
down into locked position
· Turn pump
back on and note lower pressure. Roll up backwash
hose
· Add 1 lb D.E. powder per 10
sq ft of filter area. Look on filter tank.
|
D.E.
powder in the pool?
This means you either have holes in the fabric of
the grids, or a crack in the manifold that the grids
attach to. It can also mean a broken air bleeder
tube or assembly. Finally, D.E. in the pool can
mean that the multiport or push-pull valve is allowing
powder to bypass the filter. You will notice this
most when adding new D.E. powder after backwashing,
but you can test this at any time. Your best bet
is to remove the grids and clean/ inspect thoroughly.
This will help determine what the cause of the problem
is.
Poor water Quality?
This could mean there is a problem with your multiport
or push-pull valve. The valve could be allowing
water to bypass the filter and return to the pool
unfiltered. You may not be running the filter long
enough. Otherwise there might not be enough D.E.
powder in the filter, or possibly too much. You
may also need to backwash the filter or remove the
grids and clean them manually. Poor sanitation,
poor water balance, and pool circulation could be
another cause, and it could have nothing to do with
the filtering at all.
How long should I run my filter each
day?
You should run your filter as much as needed.
Careful experimentation will show you when the
water quality begins to suffer. Many people with
smaller, older equipment run their systems 24
hours per day. The average would be about 16 hours.
It all depends on your system.
Leaking filter?
Most D.E. filters have a belly band clamp
with a large O-ring between tank halves. The o-ring
can become distended or flattened and may need
to be replaced if water is dripping from the center
clamp. Caution: Do Not remove the center clamp
while the pump is running, and without first releasing
pressure inside the tank. You may notice your
multiport valve leaking in one or more areas.
See sand filter info on previous page. If your
push-pull valve is leaking out of the backwash
port (where the hose attaches), the plunger either
needs replacement, or a new set of o-rings.
Filter replacement:
D.E. filters are more expensive than sand filters.
You may want to replace if your filter is old
and tired, or you may decide to upgrade efficiency
from a sand or cartridge filter. Price varies
by manufacturer
|
|
|
Filters
Freight
charges may apply to any order being shipped by freight or denoted by
truck symbol.