How to size sand filter?

[duraleigh]

Hi, Don,

That's a pretty easy one. You simply cannot buy a filter too large for your pool or pump....bigger is better.

Since you've got a good grasp on flow rates, capacities, etc., the easiest way to select a new filter would be to calculate your pump gpm first.

Once you get that ( from the manufacturer's info), then look at filters that are rated say around 25% higher than that. So, if your pump gpm is around 60gpm, chose a filter that is at least 75 or so.

I have not seen a sand filter without laterals.......my thinking would be similar to yours. Perhaps the Doughboy folks would be helpful with some technical info.

[dstarr62]

Thanks for the suggestion, Dave. I'll have to do some digging to try and find the paperwork that came with the pump, Doughboy doesn't have the GPM rating listed on their website.

Don

[duraleigh]

Don,

You may have to call them. You need the "pump curve". It compares gpm to the TDH of your system. mas985 is the guru on TDH, but if you can find the pump curve, you would get pretty close to the GPM by assuming about 30 for the TDH of an AG pool...perhaps a little less, but I'm guessing.