1 speed or 2 speed pump?

I am purchasing my 1st AG pool (18x33). I am considering a Hayward 150 sq ft cartridge filter with a 1.5 hp pump or the same filter with a 1.5 hp 2 speed pump. I was told by an online pool company that the low speed setting on the pump wouldn't flow enough water to turn on a Hayward Aqua Trol RJ salt water chlorinator and to use the chlorinator, the pump would have to be set to high speed. Is there any truth to this?? Also, any feedback to whether this is a good setup for an 18x33 AG pool would be appreciated. Maybe 1 hp or a 100 sq ft filter vs the 150 sq ft / 1.5 hp 1 speed or 2 speed pump.

Get the 2 speed. Always, always, always.

Let's see: 18 x 33 x 4' deep => 17,700 gallons. Ideal flow rate for a cartridge is 0.375 gpm/sft (the 'commercial' rate . . . which is the ONLY real, tested, rate). Eight hour equivalent volume turn-over would be 37 GPM. A 150 sft can handle up to 56 gpm . . . so that would be ideal.

I can't find a minimum flow specification for the AquaTrol : http://www.hayward-pool.com/prd/Abov...1_14023__A.htm

Call Hayward and ask

Contact us by phone:
(908) 355-7995 (U.S.)
Mon-Fri, 8 AM – 5 PM

But the flow on low should be around 20 GPM, and should be fine for the cell itself. It *might* not be fine for the safety on the unit. I couldn't find in the manual any explanation of how the low flow safety is set up.

By the way, that AquaTrol is BARELY big enough for your pool. SWCG life is DIRECTLY related to ON time. Buying oversized units means they last much longer. In your case, that might not be possible. But if you remember that the SWCG is just a METHOD of adding chlorine to your pool, you can make it last much longer.
1. NEVER use an SWCG for startup or for problems (like algae)
2. ALWAYS get the water RIGHT before turning the SWCG on.
3. Remember that the "BOOST" or "SHOCK" setting is sort of a "Kill me now!" setting for the SWCG. Pour a jug of bleach in, instead!

The best way, in your case, for a freshly filled pool, is to use our Super Simple recipe for a month: http://pool9.net/ssr/ This will not work for more than 2 months, but it will allow you get your pool up and running optimally while you learn GRADUALLY what's needed.

When you mention 'SWCG life," are you referring to the life of the cell or the complete system? Can you also give me some feedback on a Hayward 150 sqft cartridge filter with a 2 speed pump? Do the benefits of paying the extra $$$ for a 2 speed pump outweigh getting a 1 speed pump? If so, is it advisable to leave the low speed pump on 24/7 vs set to high speed for 8 hours/day?

yes; yes; yes, unless you are planning to sell within 2 - 3 year; yes.

;)

. . . and yes, I can be a bit of a S-A at times!

Cartridge filters can be used with 2 speed pumps or a timer better than DE filters, since there's no media that will collapse to the bottom of the pool when the pump is off. Also cartridge filters can operate well at ANY flow rate at, or below, their maximum flow. DE filters have minimum flow rate needed to maintain the DE coat; sand filters have a minimum flow needed to backwash fully.

Size a cartridge filter at the COMMERCIAL flow rate (0.375 gpm/sft), not the residential rate, which is bogus. That means your filter should operate at 56 gpm or less.

Quote:

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Originally Posted by PoolDoc

. . . and yes, I can be a bit of a S-A at times!

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No comment. :oops::p;)

(Am I fired now??? ;))

I'm gonna suspend your salary! ;)

(All $0.00 of it!)