Need some catridge filter info & advice...

[ljubica]

Just finishing up a long and costly pool remodel. The person who is doing my electrical hookup is a Pentair factory rep, so he wants to use all Pentair products, which is fine by me.
Definitely doing the VS pump.
He says I need to use a cartridge filter (quad 188594) because a de filter has 12 to 15 additional 90 degree bends in it. Says these bends require more pump pressure which somewhat negates the advantage of a VS pump, because it needs to run a higher RPM. Truth?
My city requires a backwash line hooked into a p-trap in the sewer system, which has already been installed.
Much thanks.

 

[JasonLion]

Welcome to TFP!

A traditional DE filter is a little more restrictive to water flow compared to the Pentair Quad DE cartridge based DE filter, but the effect is small. I doubt you could tell the difference. Also 12 to 15 90s can't be right. I count three to five extra 90s in a typical DE filter. Some might have a few more, but no way it is as high as 12.

The Pentair Quad DE does get many positive reviews here, so it is a good choice in any case.

 

[ljubica]

thanks, Jason.

 

[Divin Dave]

I agree with Jason on all those 90's being needed. I suppose its possible though, depending on the plumbing layout.
Also, whatever pressure increase they might add will not negate the Intelliflo to any noticable extent and no way will it negate the reason for having it in the first place.
I would be shocked if an increase of 50 rpm would be required to overcome whatever the pressure loss is of those 90's if you are using 2 inch plumbing. THe head loss of a 2 inch 90 really is minimal unless you are pumping high GPM over a long distance through it, which usually is not the case, or even close with a VS pump on a swimming pool.



I just did a power test on mine as an example for you.
at 950 RPM power usage is 119 watts
at 1050 RPM power usage is 131 watts
at 1150 RPM power usage is 154 watts

My plumbing is 2 inch and I have a Pentain 420 cartridge filter and there a are (8) 90 degree bends betwen the filter and the return fitting on the pool wall
I dont have a flow meter, but at 950 RPM, I'm estimating about 40GPM based upon the pump head curve chart.

 

[ljubica]

Thanks. Pool guy said the extra 90's are inside the filter.

 

[Divin Dave]

ahhh...
I was certainly thinking they were outside.
In any case though, there are tons of folks here an else where I am sure who have DE filters with no probs at all.

 

[ljubica]

Yeah, I had a DE filter on the pool before the remodel. So if this Pentair Quad D.E. filter uses DE as an element, is the only difference between a cartridge and a DE filter the shape of the grids?

 

[sargent]

Yeah, I had a DE filter on the pool before the remodel. So if this Pentair Quad D.E. filter uses DE as an element, is the only difference between a cartridge and a DE filter the shape of the grids?

That is correct. The other thing is that the quad DE might have more filtration area than your old DE filter. If that is so, it is a good thing.