Adding DE to sand filter FAQ

[Unabomber007]

Being a good forum user, I went through EVERY thread title in this forum searching for advice on how to add DE to a sand filter for better filtration.

What I've come up with is to add a little DE (little being 1/3 cup at a time) until you see a 1 PSI increase in pool pressure after a fresh backwashing. Obviously this can take some time as you have to watch/wait for any change in PSI to occur.

What I'd like to know is do I have to add DE after EVERY backwash?

[nicole12]

Yes you have to add DE every time you backwash.

[Rangeball]

And chances are good if you stay ahead of your pool, a $10 box of DE should last you years...

[Unabomber007]

Thanks for the help. Then I assume your DE layer sits on top of the regular sand as a sort of a "skimmer sock" for your sand. Kinda makes sense if you think through the flow.

Reason I'm interested is we have a new sand filter and it really sucks compared to our old DE filter. The wife bought it when the pool guys came out for the winterizing of our pool last year. They told her our old DE filters were bad and the replacement cost as identical to a new sand filter. Having checked/cleaned my DE screens right before I left for deployment two month's prior to the pool guys showing up.....they got her/us good! I'm hoping a nice DE layer will make the filter, filter better than it currently does.

[Rangeball]

From posts I've read, it may be the best of both worlds- Ease of sand use with clarity of DE.

If I ever need a new filter, I'd give serious consideration to this route...

Unabomber be bombing the bad guys?

Thanks for your service

[Unabomber007]

Glad to serve. Not so much on the bombing part though....I'm Navy.

[Jack T.]

Unabomber be bombing the bad guys?

Thanks for your service

Big time +1

Muchas gracias. . .or as a high school teacher used to say, muchos grassy-a$$

[Poconos]

If you pop the cover or valve assembly and look at the sand you'll see exactly that...a layer of DE on top of the sand. It penetrates down a little too and does blow out when you backwash. Also, there is nothing sacred about that 1 psi pressure rise. I suppose if you have a really clean pool you could add more DE and get even a closer approach to a true DE filter. I don't know if I started that 1 psi thing but that is what works well for me.
Al

[Unabomber007]

Thanks for the nothing sacred advice. I suppose as long as you don't get rediculous with the DE, more would be better. I will say that I am amazed at how bad the filtration of the sand unit is compared to my old DE one. Yeah, backwashing is "nice", but I have to backwash like crazy if the pool is really dirty (like pool opening) and backwashing uses a TON of water. With the old DE unit, I'd clean it once a season and it would be fine aside from the fact that it filtered like crazy.

Part of the reason for my buying a robotic pool cleaner was to supplement the sucky filtering of the sand unit. Well, I guess I'll see if I can pick up some more DE today unless I still have some hidden away in the garage.

[Davenj]

I started adding DE to my sand filter this year, also using skimmer socks. The difference is amazing. I turn the light on at night and can hardly see any floating junk in front of the light. Unlike before I started using the socks and DE.