Help determining size of cartridge, pump and SWCG!

Jul 12, 2015
2
Concord, NC
I have wanted an AGP for some time, and I finally talked my husband into it! We decided on and just ordered the pool - 33'x54" Sharkline Matrix AGP (28,500 gallons). We have decided on other parts, just having trouble determining the best sizes for 1) catridge(s), 2) pump, and 3) SWCG. For this size pool, the online retailer suggested a 200 SF cartridge, with a 2HP, 2-spd pump, and SWG (which was only for 18,000 gallons). From other posts I have read, I think all three of these recommendations may be wrong.

1) Cartridges. I read bigger the better for the cartridge. I'm all for cleaning less! But exactly how much bigger without being overkill/waste? Also, the larger sq. ft. cartridge(s) are all listed for in-ground pools. Does this matter?

2) Pump. I'm not sure about 2 spd. vs variable speed. Also not sure about how much HP. Don't want too much, lower energy and costs always better, but also want enough. Have noticed others mention that they need enough for vacuuming, solar heaters, lights, etc.

3) SWCG. I read you should get one that is made for more gallons than you have. If true, same problem as cartridges. The ones I find for that many gallons say for inground pools. Again, are these interchangeable for above ground/inground?

Since we are newbies, any help or guidance anyone could give, would be greatly appreciated! BTW, ease of use is important to me! My husband works a lot and I will be doing most of the upkeep/maintenance. Sometimes it doesn't matter, but if it does, I don't mind spending a little extra on the front end if it will make things more energy efficient, easier to use, last longer, etc.

Thanks!!!
 
Welcome to TFP!

I'll take a couple of these.

1. It's hard to go too big on a filter. Personally, I prefer sand for ease of maintenance. Something to consider.

2. 2hp is a lot for that size of pool, but do you have any of those other features you mention? Like solar, or plan one putting one in? VS Pumps are nice but some may not find them worth it if electrical savings can't justify it. Two speed is a nice option for just about everyone with a pool of any size, so I would say choose one over just one speed. Others will weigh in on more specifics, but that will get you started.
 
I sorta agree with Pat. I have a sand filter and while it's nice, when I replace it it'll be with a cartridge filter.

1) As he said, It's hard to go to big on a filter. I'd suggest a 300 sqft for your size pool.

2) I'm assuming that they're offering you an aboveground pool pump, and if that's the case, I'd go with a 1½ hp 2-speed. I don't think North Carolina electric cost warrants a variable speed.

3) For the most part, the inground/aboveground designation is marketing. If you decide to go with a SWCG you want one that's 1½ to 3 times larger than the size of your pool.
 
I think, you are on the right track.

I think most would agree on the filter, the bigger the better. Larger filter grids will provide less restriction which = more water flow. In turn, you can use a lower hp pump and achieve the same results as a higher hp pump with a smaller filter. Not to mention the pump will operate more efficiently when loaded properly.

Same for the SWCG, the larger the unit the more output, so you run it less which increases life span. However, the replacement cell costs a bit more.

The pump is where I disagree with most on this site. Everyone is hyped on 2 speed pumps.
IMO, Variable speed pumps offer more flexibility in addition to the minor cost savings. If anyone is buying a VS solely to save on energy, I would say true, you're wasting your money. However, if you want to have the ability to tweak your system and add on features in the future, VS is definitely the way to go.

VS also give you the ability to dial in the rpms which in turn can dial out unwanted harmonics. If a pump is only two speed and vibrates at it's fixed rpms then you will have less life on the bearings. With a VS you can adjust the rpm range to reduce vibration.
Ever have a slightly out of balance tire on your car? You'll find at some speeds it's nice and smooth and others it vibrates your steering wheel? Same concept. Vibration kills bearings, no two ways about it.

One word of warning. I would consider the location for the VS pump, as they are commutated controllers, meaning it's controlled by a circuit board that is more susceptible to heat and power fluctuation damage. So, if you choose a VS keep it out of direct Sun if possible, and install a power surge/brown out protector on it.

Just my 2¢
 
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