Cartridge conversion DIY help

[Cab968]

Hello all--

I'm looking for some advice / sanity check on a project I'm about to start. I'm new to doing this stuff myself, but fairly handy. I'm also lazy and easily confused, so the search turned up WAAAAAY to many threads for me to make any sense of. Here goes...

Current set- up:
~18,000 gallons, Quartz finish, salt, Intelliflo Variable Speed (3.0 hp), and PurexTriton 5000 DE filter (48sq ft), secondary pump for sweep, located in Dallas/Ft Worth

The tank is long in the tooth, with parts replacement adding up to more than the cost of a new unit. I *think* the Pentair 180008 FNS Plus is the modern replacement for this tank. However, the inlet/outlet location dimensions I'm seeing do not match up with what's currently in place from the multivalve--direct remove and replace doesn't seem possible--and there's not a lot of room for new plumbing twists & turns. So, I'm considering chopping it all off and switching to cartridge.

This is where I'm getting confused...not by the pros/cons of DE versus cartridge, but by the tank specs. I want to keep this 1 year old/$800 pump, I love it. Deciphering the manual, I come up with 150 GPM at priming speed (3400rpm), and 130 GPM at high speed continuous (3100rpm), with corresponding drops as the variable speed lowers.

More charts, more deciphering, and I've landed on the Pentair CCP420. I base this on the max flow of 150 GPM. Seems this is overkill for my size pool, but then I read "bigger is better" and "use the biggest the pump can handle" when it comes to cartridge....which should lesson the cleaning cycle as well.

So I turn to the forum....Does this equipment combo make sense? Should I drop to the CCP320 (120 GPM recommended)? Other than a 3-way valve to the old waste line, anything else I should consider?

Big step for me, as my pool is historically very clean and very low hassle. I'm willing to give up (arguably) a little luster for even less hassle, but....changing to new things isn't easy, so I want to do it right.

Thanks for any thoughts!

 

[Jimrahbe]

968,

You are just making this much harder than it has to be..

The IntelliFlo works great with the 420 and the 520... I have the 520 and if I wanted could wait a year or more to clean my filter.. I usually run my pump at 1200 RPM... at that speed, my filter pressure is only about 1 lbs..

I would get the largest filter you can afford... the smallest I would go is the 420...

I can't think of a single reason to every run my pump at full speed.. Right now my max is 2800, because that is what it takes to run my waterfall wall...

Thanks,

Jim R.

 

[Teald024]

If you make the switch to a cartridge type, make sure you can access the drain plug on the filter. When you install it, you can plumb up to the existing drain/waste and use a valve to make life easier. Make sure you have valves installed so that you can isolate the filter as well. Use quality valves, not the valves from a big box store. The cheap valves often will freeze up.

 

[Cab968]

Jim--

Seeing as I used to wear a similar helmet to the one you're sporting there, you can imagine I tend to overthink, with a dash of OCD, and a twist of err on the cautious. LOL

The sweep boost pump and the salt/chlorine generator both need slightly higher flow, but I don't run either of them continuously while the main pump is running...majority of the time I'm at 1500, 2350 when those two "accessories" are on.

Mine defaults to 3400ish when it first switches on to prime, sounds like I could disable that? I didn't mess with it much right out of the box, except for the timing.

 

[mknauss]

You could reduce the priming speed I suspect. As long as your pump basket stays full overnight.

I doubt the SWCG needs that high of flow. Have you tried lowering the RPM in steps to see were it stops generating?

If you could fill out a signature that would really help.

Take care.

 

[kadavis]

Another option would be the Pentair Quad D.E filters, they filter like a DE and you clean like a Cartridge

 

[mas985]

This is where I'm getting confused...not by the pros/cons of DE versus cartridge, but by the tank specs. I want to keep this 1 year old/$800 pump, I love it. Deciphering the manual, I come up with 150 GPM at priming speed (3400rpm), and 130 GPM at high speed continuous (3100rpm), with corresponding drops as the variable speed lowers.

Not sure how you got to those numbers but that pump would never be able to produce that kind of flow rate in a typical pool plumbing setup. At most, you would get around 120 GPM at full speed but that is with very large pipe (3"). In typical 2" plumbing, max flow rate would be around 100 GPM.