Pump too big for filter?

twosocks90

Active member
Jul 24, 2013
26
Blair, Nebraska
I've always had a problem with dirt blowing back in the pool when vacuuming. Essentially the filter never clogs, it just blows dirt right through.

The filter is a Waterway Plastics - Clearwater high rate sand filter 22" rated for 55gpm max.

The pump is a Hayward SP1580X15 which says 70gpm on the tag.

Am I on the right track here? I'm thinking that a smaller pump might actually work better in that the filter will actually plug up when it's dirty.

Or, can I just close the valve on the intake to slow the flow down a little?
 

CJadamec

TFP Expert
Apr 29, 2016
2,267
Quaker Hill, CT
I wouldnt add DE to your filter until you get the filter sorted out. If you are getting fine silt back when you vacuum but no sand it's possible the sand bed has channels in it from the high flow rates. If you are getting sand back as well then you might have damaged laterals. I would first try deep cleaning your filter which should fix any channeling for a while.

If you are looking to change your pump flow you can get a 2-speed motor for your pump and run the pump on low speed for everything but vacuuming. It will lower your electricity cost considerably and make you filter happier. Don't use valves to alter the flow rates in and out of your pump.
 

twosocks90

Active member
Jul 24, 2013
26
Blair, Nebraska
This is what I have tried so far:
  • deep cleaned the filter, twice
  • disassembled the filter, dumped the sand, examined the laterals for cracks, replaced the sand
  • replaced the spider gasket
I just checked the pump specs on Hayward's website. The SP1580X15 is rated for 91gpm! (depending on head pressure) That seems ridiculously high for the filter I have.

Is the 22" filter appropriate for the pool? Any reason to consider replacing it?
 

CJadamec

TFP Expert
Apr 29, 2016
2,267
Quaker Hill, CT
A 22 inch sand filter is fine for your pool, you can always go bigger with sand but the one you have is fine. By the sounds of it your current pump is pushing way more water than your filter can handle. What kind of filter pressures were you running.

If all you have in your system is a pump and a filter with no heaters or solar panels you would be fine with a 3/4hp pump. So you can either change out your motor with a 2-speed model which is probably your cheapest option or you can buy a whole new pump.

I would recommend a 2-speed pump no matter which way you go because it will save you a lot on the electric bill. You should also look to see if your power company offers rebates for switching to an energy efficient pump.
 

twosocks90

Active member
Jul 24, 2013
26
Blair, Nebraska
We have a heater that came with the pool but I've never hooked it up. Filter problems have kept me distracted.

Is a 1hp 2-speed pump appropriate considering we might want to use the heater some day?
 

CJadamec

TFP Expert
Apr 29, 2016
2,267
Quaker Hill, CT
Even with a heater a 1 hp pump will be plenty. Assuming your pump and filter are right next to your pool you should have very little plumbing head on your pump. Your electric bill will be much nicer running that pump on low speed.
 

twosocks90

Active member
Jul 24, 2013
26
Blair, Nebraska
If I put a smaller hp pump on the same impeller assembly, will the motor just run slower (at full speed) to give me less flow through the filter? Does the resistance slow down the new pump, or will it run at full speed and still give me the same flow, which is too fast.

Just want to make sure I understand this before I start spending money.
 

CJadamec

TFP Expert
Apr 29, 2016
2,267
Quaker Hill, CT
If you put a smaller motor on your current impeller you will burn out the motor. Single speed motors are just that. If you want to keep your current wet end and just replace the motor get a 1.5hp 2 speed motor for your pump. That motor can be found HERE.

Alternatively since the new motor is just as expensive as a whole new pump a good selection can be found HERE. Either a 3/4hp single speed or a 1hp dual speed should be plenty of pump and not kill your filter.
 
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