Question about Pump/Sand Filter Sizing

[NTL1991]

Sometimes people use the words pump and motor synonymously so I just want to make sure I understand completely. Are you proposing to swap JUST the motors or the entire pump with motor? As Ben pointed out, downsizing just the motor is a problem but if you swap the entire pump, that is ok.

Without any additional information, my guess is that pump is producing at least 65 GPM which is technically more than the filter can handle. A 1 HP Jacuzzi would be slightly better but still exceeding the 43 GPM spec. To get down to that flow rate, you will probably need the smallest AG pump on the market. Either a 3/4 HP Optiflo or Dynamo pump.

Can you post a picture of your current pump (entire pump, not a close up) just to make sure? Also, can you tell me the service factor off the pump label for each pump?

Sorry, for some reason I was thinking the motor was what would change the flow rate, but now I understand its not the motor but the impeller design. I'd have to swap the whole pump assembly including the motor.

Could I install the 1HP Jacuzzi Pump and then reduce the flow somehow to achieve the 43GPM? I know I wouldn't save much on electricity compared to switching to a 3/4 HP, but a new pump isn't in the cards for this pool. The supply and return piping is flexible, 1.5", I believe. Could a valve be installed to reduce the flow? Would that cause any longevity issues with the pump?

It's my aging parents pool and I'm the one maintaining it. They bought the pool for all the grand kids to use, but now all my siblings have their own pools. Right now, only my mother uses the pool, so I've been thinking about removing it and just getting a jacuzzi for her... Anyway...

Sure, I can get you a picture of the entire pump and the service factors next time I get over there.

Thanks,
Nick

[PoolDoc]

Sorry, for some reason I was thinking the motor was what would change the flow rate, but now I understand its not the motor but the impeller design. I'd have to swap the whole pump assembly including the motor.

Actually, if you are handy, all you have to do is change the impeller and the seal, and MAYBE the diffuser. You do NOT have to change the motor. You can run a big motor with a small impeller, and get almost the same electrical efficiency you would with a smaller motor. (Big impeller + small motor = SMOKE & FIRE!)

[NTL1991]

Interesting.

I don't have valves or anything on the supply and return tubing, so I'd have to drain off the water above the skimmer which isn't something I want to do at the moment. When I'm in the process of winterizing the pool, (which may be coming very soon, depending on my patience), I'll tackle the pump issue. I think I'd rather just swap the pump assemblies whole.

What is your opinion on hard-piping the pump and filter? Would that increase my flow rate, exacerbating the problem? I like the neat appearance, and the ease of adding valves and accessory items to the pool. Are there any good links here on proper piping layouts when hard-piping above ground pools? I'd imagine winterizing would be the prime concern with a hard-piped system.

Thanks,
Nick

[PoolDoc]

Hard PVC is not going to dramatically affect flow rates compared to same-size flex. I'm not sure about the issues of attaching rigid pipe to an AG pool wall, but I'd won't be really careful about that. You DEFINITELY do NOT want to create a stress point in the wall that way.