BACKWASHING A D.E. FILTER

1.    ALWAYS TURN OFF POWER TO EQUIPMENT BEFORE MOVING THE BACKWASH VALVE OR OPENING ANY PIECE OF EQUIPMENT. HYDRAULIC PRESSURE CAN CAUSE SERIOUS INJURY !!!!

2.         Close all suction valves. (Many self-priming pumps may skip this step. But if the pump does not catch prime easily, this may be needed.)

3.         Open the pump pot and clean the pump basket. Be sure to replace the basket correctly so nothing can slip past . If it can float up when the pump turns off, leaves can get past and plug the impeller!

            A.         Open any valve that needs to be opened (if any ) in the waste line.

            B.         Extend backwash hose (if applicable) and straighten.

            C.         If separation tank is used, make sure separation bag is in the tank! (AND EMPTY ALSO!)

            D.         If "spin" crank type, turn crank to break loose d.e. "cake".

4.         Place backwash handle in "BACKWASH" position. Piston type will have a lock pin or will need to be twisted to unlock, dial type (multiport) valves will have a handle that may need to be depressed before moving (continue all movement in one direction only, or you may damage the internal spider gasket), or other types may be located under the filter with a lever to move (a pipe that can be used for an extender may be helpful) or various sundry places.

5.         Turn on main pump (if valves are closed, open suction valves, main drain slowly at first, skimmers next)

6.         After prime is restored to pump and pump is running, open air relief (if any) and bleed all air from the filter.

7.         Run system in backwash mode until sight glass is clear, plus, about 2 or 3 minutes. You will probably lose a couple of, inches, of water from the pool. (This is actually very good for the pool. It gives a chance to change out some "old" stressed out water, for some "fresh" UNTREATED water.

8.         Turn off pump.

9.         Replace handle (or lever) in the normal operation position for the backwash valve, allowing normal filter operation, if backwash valve is multiport, place lever in rinse (filter to waste) position at this time.

10.       Turn on equipment, run for ten seconds, turn off pump. Repeat steps 4 through 9, two or three times to help remove diatomaceous earth ‘cakes’, by breaking them up better, by ‘bumping’ the filter.

11.       If backwash valve is multiport, place lever in rinse (filter to waste) position at this time. Run until clear. Turn off pump. Place handle in normal filter position. For piston type valves, be sure to replace any locking pins if needed back in the correct holes or twist any latch that is needed to keep the valve from opening independent of your presence and draining the pool.

12.       Add correct amount of D.E. for recharging the filter. Usually, D.E. is added through the skimmer closest to the pool equipment. If it is a closed system, separation tank must be emptied, the bag must be cleaned, and all connecting valves to the pool system must be closed.

TO DETERMINE THE AMOUNT OF D. E. (DIATOMACEOUS EARTH) REQUIRED.

Divide the Square Footage of the Filter by 5. The answer equals the number of D. E. scoops (or one pound coffee cans (true weight of diatomaceous earth in 1 pound coffee can (or D. E. scoop, is .5 pound). For initial coating of the filter, or after a filter clean, add approximately 40% more than normal.

COMMON SIZES .................... NO. SCOOPS

24 SQ.FT. ........................ 5 SCOOPS (2.5 lb)

36 SQ.FT.......................... 7 SCOOPS (3.5 lb)

48 SQ.FT.......................... 9 SCOOPS (4.5 lb)

 51 SQ.FT ............................ 10 SCOOPS (5 lb)

60 SQ.FT ........................ 12 SCOOPS (6 lb)

 72 SQ.FT ....................... 14 SCOOPS (7 lb)