Pool pumps dead and redesigning layout

[kix1979]

All of my pool/spa pumps have died. I'd really like to DIY replacement and use it as a chance to replace/change the flow of things. Currently, I have 2 skimmers (one pool, one spa) and one drain (spa) all 1.5" intakes. The main drain on the pool is leaking so it's shut off. That goes into a 1HP pump and a sand filter and then that goes back via 2 1.5" returns to the spa and pool. There is a seperate 2" intake & return line for the remainder of the spa jets (4 more) and another 1HP pump, which is dead.

Am I crazy to think I go to a 1.5 or 2HP pump, a new DE filter and just nix the extra spa pump with some plumbing and valves?

Also, sizing seems to care about the intake pipe sizing, but does the return not matter because there are lots of jets or is the return subject to the same GPM ratings and should be considered?

 

[acroy]

I'm a relative newbie here, but... I'd suggest get yourself a 1.5 or 2hp 2-speed pump and plumb everything through it. Use enough valves/manifolds to control where water is pulled from and where it's going. This way you'll have just 1 pump, which can run on Low, very efficiently, for long periods of time for circulation. And when you want to get the spa going full speed, kick it to Hi, maybe move some valves, and off you go. FWIW only!
cheers

 

[mas985]

You could share the plumbing with the pool and jets but I think it is not a good idea to run high volumes of water through the filter and pad other pad equipment. You would be better off having a separate high HP pump for the jets and using a low HP 2 speed or variable speed pump for the pool. That way you can use low speed for general circulation and save a lot of money in energy costs, assuming you care about that.

 

[kix1979]

Didn't really think about the filter side of things... The pool is only 12k gallons, so I think 1.5 or 2HP might be overkill on pressure for only 3 intake ports. Does the return factor in on the pump sizing at all, as there is one to the pool (2 jets) and one to the spa (1jet)?

 

[mas985]

Plumbing size is important but if you go with the smallest pump possible or use a variable speed pump for the pool, it becomes less important. You really don't need much in the way of flow rates for a pool. The spa jets need the high HP but not a pool. Just to give you an example, I am now using a 1/2 HP 2 speed pump for my 20k pool and have more than enough flow rate. Full speed I get about 70 GPM without solar and about 50 GPM with solar. Half speed without solar is about 35 GPM.

 

[Guest]

Anything bigger than a 3/4 HP pump is way too much for that size of a pool. Look at Mark's (mas985) layout and consider going that route. A bigger pump is a waste of money and electricity in your case. And, again, like Mark said, keep your jet pump separate. That way you can turn your jets on and off as desired, but use the circ pump to keep filtering and heating.

 

[kix1979]

Ok, so I'm good on all of that. As for the filter, a Hayward DE3620, I picked it up yesterday and it is already assembled. Do I need to go get a torque wrench and check it or do they come ready to be installed?

 

[mas985]

Keep in mind that the DE3620 design flow rate is only 72 GPM. Unless you have a lot of head loss in your plumbing almost any pump will exceed that. Frankly I don't why manufactures design filters with such low flow rate specs when they know there is a good chance that it will be exceeded. The filter may not be damaged or anything if you exceed that by a little but it is certainly a consideration when choosing a pump.

 

[kix1979]

Erm, my bad. I'm actually going with a DE4820 and a 1HP Hayward Super II for the pool. Based on everyone's recommendations I will replace the other pump later for the spa jets, it makes more sense when I think about the filtration side of things. Do most people do unions on the filter valve and pump these days?

 

[Guest]

Do most people do unions on the filter valve and pump these days?

No, but only 'cuz they are cheapskates :lol:

We do, and it makes life a lot easier down the road. Done right, there are no leaks and makes working on or replacing much easier when needed!

 

[kix1979]

Well the equipment is installed and plumbing is great, minus a small leak on the return side of my pump (darn union valve...) but thanks to everyone here I managed to DIY and save myself about $1600+! Next up is to replace the old wiring box/timer that the pump is wired into.

Thanks!