Beginner DE Filter Questions

[CJacksonLASD]

Hello,

I am a newbie with pools. My original Hayward DE4800 pool filter 48 sq ft. (no idea how old it is, guessing 6+ years old) casing cracked spewing water everywhere. Was lucky to find a replacement Top and Bottom housing unit on Ebay (Hayward no longer makes nor sells this model).

I reinstalled the housing units, with some finess (the parts did not perfectly align, with changing Hayward models over the years, but was able to set it all up) got the leaks to stop.

I hosed off the DE Grids, and turned the pool pump on, added 8 lbs of DE, added 4 gallons of chlorine, and starting pressure was 14 psi. The pool pump has been off for 4 weeks while the pump was broken so the pool was cloudy with dirt and debris on the bottom of the pool and the sides of the pool were slightly green. After 2 hours the pressure rose to 24 psi, and by hour 6 the pressure rose to 32 psi, and I noticed slight drips from one of the bulkhead intake valves.

I am guessing the drips of water was a result of the high pressure in the filter. When I cleaned the grids I replaced one that was ripped. The others were discolored slightly green from algae drying on them while the pool was off.

QUESTIONS:
(1) Why did the pressure rise so fast?
(2) From reading the pool school section, should I just try backwashing the filter (maybe the filters are clogged all ready with the dirt in the pool)?
(3) Should I take the grids apart and clean them (3 hours in water with dishwasher detergent then 3 hours in 10:1 water / muriatic acid)(I have never cleaned my grids before, only replaced them when they were ripped)?
(4) When adding the DE at first I saw a little cloudiness entering the pool through the return line. Is this normal for a little DE to sneak through the filter and go back into the pool, or does that mean there is a hole in my grids?

Any suggestions would be appreciated, Thanks.

 

[jblizzle]

1. Because your pool sounds dirty and with algae. DE filters are very efficient at catching stuff. You should backwash when the pressure rises 20-25% over the clean pressure. Really sounds like you need to SLAM the pool.

2/3. At least backwash, but a thorough cleaning would not hurt.

4. You should not see DE returning to the pool when adding it, although some people always seem to. You can add it on the rinse setting if have it.

I would do a good examination of the grids and clean them and then follow the SLAM process ... You may want to start on recirculate until the algae is dead and then filter it out.

 

[Richard320]

QUESTIONS:
(1) Why did the pressure rise so fast?
(2) From reading the pool school section, should I just try backwashing the filter (maybe the filters are clogged all ready with the dirt in the pool)?
(3) Should I take the grids apart and clean them (3 hours in water with dishwasher detergent then 3 hours in 10:1 water / muriatic acid)(I have never cleaned my grids before, only replaced them when they were ripped)?
(4) When adding the DE at first I saw a little cloudiness entering the pool through the return line. Is this normal for a little DE to sneak through the filter and go back into the pool, or does that mean there is a hole in my grids?

Any suggestions would be appreciated, Thanks.

The high pressure is probably all the sludge you're filtering out. It's not uncommon to load up in hours when clearing a swamp. I would say backflush and refill with 80%. And once the pool is clear, then do a full teardown and scrub things and use 100% to recoat things.

The burst of cloudiness is worrisome. If it happened as soon as you turned on the pump, then it might just be residual that snuck in someohow when it was torn apart. If it happened only after you added DE, then there's a crack, or a tear, or something not seated right. It shouldn't be leaving except through the waste port when backwashing. In that case, you have no choice but to tear things down and look for the leak.