What size sand filter do I need for my pool?

[SCpoolOwner]

While the pool is down for the winter, I've decided to move away from my current cartridge filter for various reasons. I think I've decided I want to use a sand filter with a little DE added to it. The problem is that I've read conflicting information on the size of sand filter that is needed. I've read that two turnovers in 8 hours is sufficient for a filter. Then I've read that about 3.0 feet of filtering area is recommended for a small IG pool.

Here are my current pool specs:

Astral Pools USA pump - IGP2010 1HP:
http://www.astralpoolusa.com/index.php? ... Itemid=310

I have a replacement pump (Pentair 3/4 HP) as a backup since I thought my old pump died about a year ago but I got it fixed before the replacement one arrived.
http://www.pentairpool.com/pool-owner/p ... ps-165.htm

A pool calculator says I have about 8600 gallons of water in my pool, which is pretty small for an IG pool.

I'm looking at three sand filters due to cost/benefit ratio:

1) Hayward 18" S180T (can purchase for about $190 shipped)
2) hayward 21" S210T (can purchase for about $240 shipped)
2) Hayward 24" S244T (can purchase for about $305 shipped)
http://www.hayward-pool.com/prd/In-Grou ... 5516_I.htm

I know bigger is better for a filter but we don't have a ton of money to spend at this time. If I have to backwash every month that is OK but I don't want to backwash every week.

 

[Bama Rambler]

Given your situation and having a 1hp pump I'd go with the 210. If your pump was a 2-speed you could get by with the 180.

 

[SCpoolOwner]

Thanks Bama Rambler!

The 18" is out for sure. I'm probably going to try and get the 24".

 

[CUTiger78]

I've got an S244T.

No matter which of the 3 you get (and, for <9K gals, I'd go with the S180T), put unions in so that you can get the top of the filter off w/o cutting pipes. If you ever want to get into the filter, you'll be happier. With getting into the filter in mind, have you considered a a side-mount model, like the S210S?

 

[MFL]

A few simple calculations can be utilized to properly size a sand filter.

Volume divided by desired turn over (in hours), divided by 60. (60 mins)

Lets say for instance you want a 4 hour turnover

Pool = 8600 Gal, divided by four, divided by sixty = 35.8 gpm This would be your target flow rate to achieve your 4 hour turn over.

An easy way to further calculate your GPM into required square ft of filtration area is...

15 gpm per sq ft, divided by 38.5 = 2.38 sq ft or required filter area for 4 hour turn over.


Now if you want to turn your pool over every 6.4 minutes...give me a call... :-D

 

[SCpoolOwner]

Thanks for the follow up replies!

I was able to get the S244T through an Amazon open box special for $253 shipped about two weeks ago. The freight company is supposed to deliver it tomorrow morning. I'll assess what plumbing components and I'll definitely use unions.