How do I match a pump to a filter?

[Gilly McFinn]

I know. Surely this has been covered, but I cannot quite find the answers I need.
I have an Intex sand filter by Hayward, model sf 70110. (above ground, btw)
The motor that came with it, 1500GPH / 25GPM, same model #, has seized. It was rusted solid. I couldn’t even get the screws out to try to fix it. I threw it away.
The filter specs show GPM-30, which I think is a little weak for a 10,600G pool. It was often cloudy and vacuuming was really a chore.
My problem is this- I can find no information suggesting if I can go with a higher GPM or not.
The filter says Maximum Working Pressure- 30PSI. Does that mean that’s all it can produce with the original pump, or is that all it can take?
Even if that’s all it can take, pumps don’t show PSI.
The next problem is, the next step up that I’ve been able to find is around 2400. That’s a pretty significant jump. Is that OK?
I’ve seen Amazon reviews for 5000GPH pumps on pools like mine. They said it worked great, but they never say what model filter they have.
I’m so lost. I’ve been researching this for 2 weeks and I’m more confused now than when I started. I almost ordered the 5000GPH, but 12hrs of reading later I don’t know whether to scratch my watch or wind my butt!
Thanks for your time.
Finn

 

[jblizzle]

Welcome to TFP!!!

The manual for the model sand filter you posted states a maximum working pressure of 50psi ... this is the same as all pool equipment and no pool pump is actually capable of producing the pressure. So, nothing to worry about there. I doubt any Intex pump can even achieve 30psi.

While the pump may state 1500 or 1600 GPH, that is with no plumbing head loss. Once you add plumbing and a filter after the pump, the flow rates tend to be much reduced.

Your filter is a 14" diameter with 55 pounds of sand.

On the Intex website, they are selling 14" diameter sand filters with "2800 GPH" pumps, so I would think that going to something like that should be fine.
The current Intex 14" filters appear to call for 77 lbs of sand with the 2800 pump.

There is no danger to going to a bigger pump. The risk is that if the flow rate is too high through the sand filter, that you could push the debris through the sand and back into the pool.

For reference my Pentair 1HP Superflo pump does not get much over 40 GPM (2400 GPH) in my pool and I am certain it is more powerful than any of the Intex pumps. Their ratings are fairly meaningless IMO.

 

[Gilly McFinn]

Jeez, you make it all sound so plain and simple!
Thank you SO MUCH! What a load off!
I’m going to order the 2400GPH right now then.
So should I add another 22# of sand, to bring it up to 77#, as you mention they use now with the 2800s?

 

[jblizzle]

I do not think you should arbitrarily add more sand. It could be that the newer 14" sand filters are a little taller so they can hold more sand.
Usually you want the sand level to be just below where the filter tank starts to curve back in (there might even be a line in the tank, but I am not sure).
So you could take a look in your filter and see where you are at.

 

[Gilly McFinn]

I do not think you should arbitrarily add more sand. It could be that the newer 14" sand filters are a little taller so they can hold more sand.
Usually you want the sand level to be just below where the filter tank starts to curve back in (there might even be a line in the tank, but I am not sure).
So you could take a look in your filter and see where you are at.

Oh good. Pool sand is some expensive dirt!
Thanks again.
Now to tackle this chlorine generator that’s been sitting out with water in it for 2yrs.
It’s probably toast, but maybe I’ll get lucky. Stranger things have happened.