SWG Operation - Lessons Learned

[PatL34]

According to your test figures everything looks good. The FC at 10 ppm is your call, but if you can drop Aquarite output slowly to get the FC to about 3 - 5 ppm, you can get some more life from the cell.

If you want to bring the CH down a bit, use softened water for refill.

Otherwise for the rest, "if it ain't broke, don't fix it".

Pat

[PatL34]

Have added some extra comments regarding bleach cost vs. SWCG cost in the "Pro" section of the original post (#1).

Pat

[waterbear]

ONe thing that I am wondering about....I know that saline bags used in the medical field are composed of PVC and that acid will leach out of the bag lowering the pH of the saline solution inside of it. Could something similar be happening in a vinyl lined pool?
Food for though.

[PatL34]

Waterbear,

The only way to find out is to make some kind of a small pouch or bag of the vinyl liner, without using any kind of glue or PVC cement, add some distilled water, and see if the pH goes down. Then add some salt from a 40 lb. bag of solar salt and check the pH again.

Pat

[waterbear]

Waterbear,

The only way to find out is to make some kind of a small pouch or bag of the vinyl liner, without using any kind of glue or PVC cement, add some distilled water, and see if the pH goes down. Then add some salt from a 40 lb. bag of solar salt and check the pH again.

Pat

So now all we need is someone with some extra liner material and a heat sealing machine willing to do the experiment!

[PatL34]

I don't know what the effect of the heat sealing machine would have on the chemistry of the vinyl, so I was thinking of a container shape in the form of a bag or pouch with holes near the edge for a drawstring so as to hold the sides up.

Pat

[nater]

Bump. I think this one should be a sticky-lots of good info.

[Katy-Texas]

Just to add my 2 cents.

Have a 26000 gal in-ground plaster & gunite salt water pool for just over a year here in west side of Houston. Chemicals added are:

1) 1 gallon of acid every ~10 days to keep pH down in summer, about 1/2 that in winter.

2) Some cheapo Algaecide when I had some algae in skimmer entrances last summer. Then I read this forum and realized I was too cheap on power and upped my pump time to raise my Cl level to 2 since which I've had no more algae problem.

3) Added 3 x 4.5 lb jugs of stabilizer this spring when 1 year old as almost all disappeared over winter.

4) Couple bags of salt every 3 months, mostly as big rain dump overflows pool via overfill line to street thereby diluting the salt.

Teenage daughters want shower 1/2 time after pool, I never do, feels great.

I do still have quite a bit of spalling of flagstone (sandstone) coping, friend said he heard it was because I had salt pool? Whatever the reason I would not do flagstone again.

Lastly, all my friends with conventional Cl pools still have upsets once-twice a summer/year and get sold tonnes of chemicals from local stores.

Question 1, my pool builder said better to run salt generator at 50% for longer than 100% for shorter (and thereby save power) as hard on salt generator, unknown why?

Question 2, from reading this thread, sounds like vinyl salt water pool owners add way less acid than plaster owners, so something is going on with plaster. My plaster seems to be etching, ie becoming more porous, over time. Is that a negative side effect of salt plaster pools?

Thanks to pat for kicking off great thread, toodles.

[PatL34]

Thanks Katy for your response.

Your PB is correct in running longer at 50%, and once you have gotten used to the SWCG, you may be able to lower that setting.

The etching you mention could be a function of very low pH, if you are adding Muriatic Acid too much. pH should be between 7.2 - 7.6.

I still have not been able to understand why vinyl pools maintain a steadier pH than plaster pools. Plaster pools will always raise pH because of leaching from the walls, and particularly for new pools that are still being cured. How soon did you add salt after filling?

I waited at least a month before adding salt, after a replaster with Diamond Brite. Another possiblity is if sand was included in the plaster mix. This can be a reason for etching. That's why I had to replaster. The current pool plasterer demonstrated what happens when you don't have sand, by pouring 2 gallons of raw muriatic acid on the steps as the pool was filling up. If there had been any sand, it would have etched immediately.

Hope this helps.

Pat

[Katy-Texas]

Hi Pat

You say that I may want to lower SWCG from 50% I assume to extend it's life, but then I'd need to circ longer thus more power, guess it's a trade off.

Keep pH in 7.2-7.6 so don't think that's why etching.

Similar to you, pool builder added salt about 1 month after plaster & fill.

Thanks for ideas . . . cheers.