Appropriate Size SWG ?

[gregmatt]

Hello all,

New pool owner, about to convert to SWG, but still unsure what to buy.

After doing some reading, there is a wide variety of opinions on, "How to size a new SWG"? Some say, an 18,000 gallon pool should use an 18,000 SWG. Other say, no choose one 1-2 times the gallons you have so it doesn't work so hard.

I am considering the Hayward W3AQR15 AquaRite for $1111 (40K gallons), since it's basically the same price as the comparable models for a 25k gallon.

Any thoughts and or suggestions welcome.

Thanks!

 

[lager1829]

Yes go for the 2X size otherwise you need to run the smaller @100% 24h per day

 

[Jimrahbe]

G,

Keep in mind that cells are rated with running at 100% output and 24/7.. So, to make a 18K cell work in an 18K pool, you would have to run it max out and all the time.. Does that sound like something you want to do??

For an 18K pool, I always recommend a 40K cell.. Having a cell that is too big is never an issue.. Having a cell that is too small is always an issue.

This is one of those times that you get what you pay for...

Thanks,

Jim R.

 

[Rossterman]

Also remember the longer the runtime the shorter the life As well. Each cell will generate a finite amount of chlorine over it’s life. A cell running at 100% 12 hours a day will last twice as one running 100% around the clock. Oversized means less run time at lower output % which equals longer life.

 

[gregmatt]

Thanks all. You confirmed what I was thinking.

 

[newdude]

The other added bonus is that the size and price are not exactly matched. Often you can double the size (and the lifespan) for only 20% more. That math works very well in your favor considering the investment you are making.

 

[Stoopalini]

Is biggest always better? Meaning, on my 14000 gal pool, an IC40 would be more than 2x ... but would it be “better” to go with an IC60? Or are there diminishing returns in over sizing.

 

[newdude]

Yes there does come a point where the electronics would fail before the plates in the cell. Nobody knows where that is though. An IC40 would be plenty for you. My point was in regards to the original over sizing from the IC20 to the iC40. It will get you double the life without anywhere near double the cost.

 

[setsailsoon]

Greg,

I'm so glad I followed TFP ~2x guideline. Had mine in for a little over a year. Also I discovered that the CYA level is way more important than I realized. My pool is screen enclosed so I thought that wouldn't matter as much. Boy was I wrong! I had "stay on the low side of CYA" mentality so I could use pucks for frequent travel that I really just barely raised it. As soon a it got hot FC started dropping. Thought I had an algae issue but passed OCLT and pool looked great. So raised CYA to 70 and FC started rising like crazy. That was a year ago. This year CYA dropped from massive rains twice. Same exact thing happened. CYA had dropped below 50 two times. Below are recent test logs. Virtually no changes in weather just raised CYA from 50 to 70. Run time and % power stayed identical... looks like I may need to reduce run time.

Chris