New pump - did I overdo it?

[Onslow]

I recently picked up a Doheny house brand 1.5hp pump. The existing filter is a Hayward 210T and from what I can tell has a designed flow rate of 44 GPM. The pump is apparently 83 GPM (dumb I know, wasn't even thinking about it).

There is some, but not a lot, of sand settling onto the backwash discharge (about 10" at most out). The pool, which I'm now cleaning up, has gone from green to brown but has some leaves at the bottom form winter.

Wondering if I mis-ordered? The PowerFLo Matrix that this pump replaced also had a similar GPM in the 80s or so. Even the lowest 3/4 Doheny has a 62 GPM rating so just trying to figure it out.

Is this (sand during fist couple of backwashes) normal or did I really mess this one up?

Thanks.

 

[Onslow]

Short follow up. Waded into the pool and there are a few small mounds around the jet.

 

[mh_jenkins]

Hi Onslow, Tech talk... I have learned that the pump flow rate listed in GPM (Gallons per minute) should be LESS than the rated Flow Rate of your sand filter. You should check. Also the diameter of your piping is important too. For example 1.5 can handle <=~42 GPM, 2 in <= ~75 GPM, 2.5 in <=120 GPM. If your pump GPM is higher than the sand filter OR the piping diameter, then your motor will labor and will not last as long as expected. Replacing a sand filter is not so difficult, however replacing piping to a pool can be a job. Hope this helps.

 

[OldPoolBoy2]

Sand in the pool would usually mean that it has gotten thru the lateral, generally this would point to a broken lateral. You should not be getting it out the discharge either unless you had a very high flow rate. That being said I think it might be possible that the sand level is so low that on backwash there is no resistance which in turn allows for higher flow rate during backwash, (obviously the level has gotten lower from sand loss as you described)
.... The other thing that comes to mind is possible channeling in the sand filter.... Have you "deep" cleaned it recently. Be a good time to pull the multivalve valve check the sand level, shop vac out the sand and check the laterals.

As far as flow rate and your pump you can always get a smaller (less GPM) impeller, it will move less water and it will require less HP. You can safely go to a less gpm impeller and not harm your motor,you cannot go the other way.

 

[Onslow]

Good advice - thank you both. I'll start the deep clean and see what lies below!

 

[Onslow]

Quick follow-up to close this thread. Busted laterals, big time. Replaced and all is good now.

I did send the pump back and replaced with a 3/4hp. Kinda weak stream out but meets the 10 psi recommended on the filter handle label.