New from new york

[PoolDoc]

On a 17k gallon pool, you would ideally have a flow rate of 36 GPM (8 hour turn-over). That translates into a 21" ID sand filter @ 15 GPM. You'd want a 18 sft DE filter or a 96sft cartridge filter. Cartridge filters can be oversized without limit; DE and sand filters cannot.

The 'real' flow rates for filters are the ones listed for public pools:

sand => 15 gpm/sft
DE => 2 gpm/sft
cart => 0.375 gpm/sft

The Superflo pump may, or may not, be too big. Two questions:
1. What is the exact model of the pump, and what are the electrical ratings on the motor?
2. Are you handy enough to take the pump apart, and re-assemble it?

[rwb1967]

Pentair Superflo model # sf-n1-1a 1 hp pump .....

voltage=115/230
full load amps=14.2/7.1
hp=1
sf=1.25
sfhp=1.25

not sure if any of that helps..? Yes , handy enought to do what needs to be done.

Thanks

[PoolDoc]

OK. That model is the 1hp Up-rate standard efficiency Superflo.

Pentair info page
Manual

Here's an option:

Pentair 350088S with SWTCH SQFL 3/4 HPF 1A 60-Hertz 2SP ALMD Motor Package
Pentair 355067 Impeller Assembly Replacement Pool and Spa 1 HP Inground Pump
Seal and gasket kit at A1PoolParts.com

Check the manual, and confirm, but I believe those are the right parts to convert your pump from a standard (low) efficiency 1HP motor to a high efficiency 2spd motor - for around $250.

You'll want to run on LOW all the time, except when priming, vacuuming or backwashing. LO moves about 1/2 the water that HI does, but uses about 1/6 the electricity. Your flow will be much better matched to your pump -- and your water may be clearer as a result. Your electric bill should go down a bunch!

A couple of tips:

1. If you have a timer, you may have to put a check valve in the piping just ahead of the pump, so it doesn't loose prime when it's turned off. The Jandy check valve is available from Amazon and is a good choice.

2. You'll need to watch your backwash discharge. If you find sand coming out with the backwash, you'll need to put a valve on the discharge (a cheap PVC ball valve is fine) and throttle it to slow the flow. LO may be too low to fully backwash, but HI may be too high.

[rwb1967]

I'm actually thinking of upgrading to a hayward 24 or 27 inch sand filter...I looked at the 24 inch and it seems to be enough flow to handle the Pentair pump...any thoughts?

[PoolDoc]

Upgrading filters is ALWAYS a good idea. Even so the 2 speed works better with sand filters.

The slower the flow, the better the filtration with sand. 8 hours on LO will produce higher water quality than 4 hours on HI . . . and will use less than 1/2 of the electricity!

With the larger filters, you won't need a discharge throttle valve, but will definitely need to backwash on high.

[rwb1967]

Another question ...should I plumb the pool with 1 1/2 or 2 " pipe? ....what is the benefit of 2"if any beside less pressure?
Again...thanks for the help

[PoolDoc]

Before I try to answer ?'s like that, complete the pool equipment form: http://pool9.net/pf-equip-form

In the notes, include info about extra equipment, number of skimmers, and number of returns.

[rwb1967]

Form completed.

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