Quad de vs cartridge - lil help?

[PoolguyinCT]

Hi - I need some input please.
I am going to install new filter at my in laws snowbird house in Florida..

My go to is the clean & clear cartridge , because it will easily go a year with out a tear down on the screened in pool.

I have never used the quad de - how is Filter cycle ?

My hang up is they are rated as DE vert grids sq ft wise?

I’m replacing a vert grid 36 & was going to go w a 320 C&C cartridge.. am a novice with the quad de , I can hit ample flow rate with either. I’m hung up on the sq foot thing..

Am I comparing Apple to apples surface wise??

Thank you!

 

[mas985]

In terms of flow rate, you can use this chart that is in the Hydraulics 101 sticky. This shows the three filter types with the same flow rate ratings.

However, the same flow rating does not mean the cleaning cycles are the same. That seems to be related directly to the area of the filter. The larger the filter, the more time between cleanings. Sand filters have the smallest area and thus the more frequent cleanings. Then comes DE and cartridge is the longest between cleanings. Also, DE traps smaller debris and so is more likely to require cleaning sooner than a cart with the same size filter.

Also, there is a big difference when you consider backwash valves. They tend to very high in head loss so can have an effect on flow rates. The cartridge usually has the lowest head loss of any filter.

From the Hydraulics 101 sticky:

 

[JoyfulNoise]

You can plumb a QuadDE without any backwash valve. My QuadDE 100 on a 16,000 gallon open pool (low debris load and I use hair nets in the skimmer) can go a full year between cleanings, no backwashing necessary.

 

[mas985]

The table above shows the DE filters with and without backwash valves.

 

[PoolguyinCT]

Thanks guys!! - I appreciate the thoughtful responses. I did a cheapskate move & pulled a 420 cartridge from my shop & shipped it down.. gonnabe a working vacation[emoji41].

Btw that’s a nice chart above!

 

[JoyfulNoise]

As Kim would say ....

 

[PoolguyinCT]

Who published that table? Or is it a tfp grassroots compilation!!

 

[mas985]

I created the tables from publically available information. There are several more in the hydraulics sticky.

 

[PoolguyinCT]

Very cool. Fluid engineer day job??

 

[mas985]

Electrical engineer. But fuild dynamics is not a huge departure. It is all physics.

 

[JoyfulNoise]

Electrical engineer. But fuild dynamics is not a huge departure. It is all physics.

Hahahaha .... under statement of the year!

Mark, there is a huge difference between the fluid dynamics taught in physics departments (where all fluids are incompressible, no heat is ever lost and all constants have unit value) and the fluid dynamics taught in MechE where you actually have to get the answer correct to within two decimal places

 

[PoolguyinCT]

Cant fit pounds in a one pound bag ( pounds of what is real ? [emoji12])

 

[mas985]

Mark, there is a huge difference between the fluid dynamics taught in physics departments (where all fluids are incompressible, no heat is ever lost and all constants have unit value) and the fluid dynamics taught in MechE where you actually have to get the answer correct to within two decimal places

I did not say it was learned in physics classes. What I said was it is based on physics. All engineering is based on physics.

 

[JoyfulNoise]

As any physicist will tell you, engineers exist to ruin their beautiful equations by linearizing everything, finding an "approximate" solution and then adding back in a 3X margin of safety

 

[mas985]

Classics:
http://www.cs.northwestern.edu/~riesbeck/mathphyseng.html

 

[JoyfulNoise]

Classics:
http://www.cs.northwestern.edu/~riesbeck/mathphyseng.html

BOOKMARKED!!!