what truth to better oversize initial purchase of SWG Cell ?

susa

Well-known member
Oct 31, 2010
578
Deep South
am being told (I am a first time buyer..) that 'tis best to oversize my initial Aqualine/Swimpure SWG purchase.

so, new pool is just 15k gallons but I am told .."you better buy the 40k version.." as it will work less and last longer.

just this morning I interviewed a fellow at one local poolsupply place and he tells me his system is 5 years old, had SWG installed when built 5 years ago and 2 years out the Cell failed, replaced under warranty, then again at 4 years the Cell failed.

I asked him about cost and he said first one, no cost, second time about 250.00 but he said it was all worth it and he has no regrets.

Is that about correct and am I missing something in my expectations or explanations?

Thanks.
 

dmanb2b

TFP Expert
LifeTime Supporter
Apr 4, 2009
3,734
NY
Good to oversize, but 40k on a 15K gal pool is overkill IMHO. A cell sized for a 25K gal pool should be more than enough. Cell replacement costs vary by manufacturer with avg cell life being around 5 years.
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
The cells have an expected life rated in amp-hours (similar to a light bulb). The logic in over-sizing the cell is that you will have to run it less in order to maintain the same FC levels. For example, you'd have to run a 40k cell only 3/8 as long as you would a 15k cell. So, according to their rated lives, a 40k cell would last 2.67x as long as as 15k cell while costing only a little bit more. However, bad water management will ruin cells quickly regardless of their size.

I have a 40k cell on a 11,000 gallon pool. The cell is now 5 years old and still works perfectly.
 

susa

Well-known member
Oct 31, 2010
578
Deep South
> bad water management will ruin cells quickly regardless of their size.

describe a little more on common "bad management" practices ?
PH?
Overuse of dispersant XXX?
Something else?

Fellow at the store that I mentioned in the OP, was buying a ****load of chemicals, clarifiers,declauders,demystifiers,black algae,purple algae, ok you get the point but he DID spend over 100 clams in trying to resolve some alien thing growing, yet, claimed to be happy. Almost like a SWG evangelist ?

Me, I just want to learn and buy the right stuff and use it correctly.
 

dmanb2b

TFP Expert
LifeTime Supporter
Apr 4, 2009
3,734
NY
bad management from a SWGC perspective would be high CH and PH above 7.8 and running the cell at 100% all the time. The 1st two cause frequent scaling and the later will prematurely wear your cell. Also the fist two are the main reason we advocate getting a good drop based test kits, to ensure your water chemistry is within recommended levels as noted in pool school.
 

Davegvg

LifeTime Supporter
Nov 30, 2008
345
Dman has it right.


Add to that most people just ignore the thing till it stops and rarely actually try to clean off the scale that does build up.
Even the "auto cleaning" reverse polarity units seem to build up over time.
Every now and then an acid dip in a bucket will keep it clean and it will last longer.

Oversize is good.

Uncle Dave
 

susa

Well-known member
Oct 31, 2010
578
Deep South
> high CH and PH above 7.8 and running the cell at 100% all the time.
> most people just ignore the thing till it stops and rarely actually try to clean off the scale.

that would appear to have been the reason the person I mentioned buying the ****load of chemicals, I even asked if they had pressed the Diagnose button on the Control Panel and got a quizzical "No" for an answer.

am setting up my 240v electrical supply next couple days, installing a new service box outside and will then decide which equipment to install.

thanks.
 

Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
23,626
SouthWest Alabama
The accepted rule of thumb is to oversize the cell for all the reasons listed above. But don't go much over 3 times the size of the pool.
 

acroy

Well-known member
May 11, 2010
186
Dallas TX
oversize is good - up-front cost difference is minor.
I am in the other boat: 24k cell on a 33k pool :( not sure why they did that.