Pump Size?

[cwmoody]

I am looking for help in choosing a replacement pump. My old pump is a Hayward 1HP pump (single speed). It has an AO Smith motor Model C48L2N134D2, Serial Number 30508FM, RMP 3450, Amp 18 6/9.3. My pool is 45,000 gallons with an average of 37 1/2 feet of head. My filter is a Hayward 300 pound sand filter Model S244T with a filtration rate of 20 GPM. According to turnover rates, it seems that my filter is under sized. However, I have always ran my pump 24/7 and it has worked well in the past. Sometimes it takes a little longer to clear up dirty water than what I would like, but that is probably just me being impatient. So my questions are: Should I just replace my pump with a two speed 1 HP pump? What other specs should I look at? If I switch to a two-speed pump, do I need to go up in size? Can I even go up in size with my filter? Thanks.

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I may have been looking at the wrong numbers on the filter. The filtration rate is 20 GPM, but the filtration and backwash design flowrate is listed as 62 GPM.

 

[mas985]

If the pump (wet end) is in good condition, I would just replace the motor with a two speed. No plumbing changes required and usually cheaper than replacing the entire pump.

But what is the pump model#?

 

[cwmoody]

I cannot find a model number on the pump itself anywhere. The pump is quite old so I wanted to go ahead and replace the entire unit.

 

[mas985]

Ok then the MaxFlo SP2307X102 would be a good choice. BTW, how did you get to 37.5 feet of head? Did you measure that?

 

[cwmoody]

Thanks! My main drain line is approximately 45' and my skimmer is approximately 30', so I averaged the two.

 

[mas985]

Head loss in pipe is proportional to pipe length but it is not equal to it. It is a far more complicated calculation than that and it also depends on the types of fittings, valves, filters, heaters, etc.