Ozone smell

[CarlD]

Of COURSE they said you need calcium in an above ground pool! That's what they do. You buy and another $50 goes in the register. Ask them what the calcium actually DOES in your AG pool and you'll get a lot of waffling.

Calcium is used to protect the calcium carbonate in pool walls in the cement, mortar, shotcrete, plaster, etc. It keeps it from leeching out. Therefore it's useless in vinyl pools.

[AnnaK]

You mean I shouldn't have bought that stuff and dumped it in????

Just kidding.

I said thank-you for the water test and I said I'd give the calcium a miss this time since my vinyl liner didn't require feeding.

AnnaK

[waterbear]

Calcium is used to protect the calcium carbonate in pool walls in the cement, mortar, shotcrete, plaster, etc. It keeps it from leeching out. Therefore it's useless in vinyl pools.

BUT there is some evidence it is useful for fiberglass pools!

[CarlD]

BUT there is some evidence it is useful for fiberglass pools!

I don't know the chemistry of FG pools too well, but I cannot imagine how calcium interacts with glass and the resin used to bind it. I'll let Ben and Chem_Geek work that out. People forget: Fiberglass is actual glass--super-thin threads of it.

[waterbear]

I don't know the chemistry of FG pools too well, but I cannot imagine how calcium interacts with glass and the resin used to bind it. I'll let Ben and Chem_Geek work that out. People forget: Fiberglass is actual glass--super-thin threads of it.

Actually Carl, I've done quite a bit of research on this and have discussed it some with Richard. There is some evidence that the calcium (actually, the harder water) helps prevent cobalt spotting (black spotting), which is a problem with fiberglass pools. (Cobalt leaching from the gelcoat. Cobalt is a component of the resins used in fiberglass.). Cobalt spotting is probably only second to iron staining as a downside to fiberglass pools but both seem to happen much less with higher CH. (For example, my own pool is filled with soft water and I had frequent problems with iron stains, usually requiring an ascorbic acid treatment every 6 months. Once I raised my CH to around 350 ppm about 2 and a half years ago I have not had ANY staining problem and have not needed ascorbic acid.) However, unlike iron staining, cobalt spotting if often difficult or impossible to remove. There has been discussion about this on a different forum, btw.