DE in a sand filter???

[cschnurr]

Went to the 3 pool stores to pick up DE. They didn't have any, but had an "equivalent" thats supposedly better than DE.

I tried it on the weekend, waiting only about 5 minutes, before reading the pressure gauge. Pressure rose very little, so I put in another cup, 3 in total.

Later in evening, checked pressure gauge and it was up 8 lbs.
So I had to backwash it away and start over.

How long should to wait for the pressure to increase?

[medvampire]

cschnurr

It takes mine about 20 to 30 minutes to raise. I get a 2 to 3 psi per 1 and a quarter cups. The de does work but I have noted it takes a few days to really notice the diffrence.
Steve

[Poconos]

cschnurr...Carl,
What was the stuff they sold that is supposed to be better than DE? Just curious. All I know is the approximate time for the presssure to stabilize when adding DE. The amount you add to get the target 1 psi rise is also very dependant on the filter size.
Al

[CarlD]

It's this new stuff that folks have written about that's some sort of DE substitute that's less dangerous to breathe. Some sort of fibrous stuff. I have NO idea how it works, or how well it works, but it's supposed to be OK to use with a cart filter, unlike real DE.

[waterbear]

There are two kinds of DE replacements...One is cellulose fiber and the other is perlite, a type of volcanic rock. I have no info on the filtering ability of either as to how small they will filter. I know the cellulose one can be used with cartridge filters since it doesn't clog the reemay polyester filter material. The perlite is still a silceous (glass) rock so it still might be dangerous to inhale. don't really know.

[cschnurr]

The stuff I was sold sounds like the cellulose material Waterbear mentioned.

It had a generic name like "DE filter additive". Instructions stated for DE filters or sand filter additive, and also stated it was 5x the efficiency of DE. It was off-white in colour and extremely lightweight.

It was $13 Cdn, for about 3-4 cups.

My question to the pool store where I purchased it was if it is 5x DE, how can so little of it spread entirely across the filter. She didn't know.