I don't know if there's any interest in continuing this discussion (civilly of course) that started in the infamous "Ever know of anyone who doesn't like a SWCG pool?". If so, let's have at it.
Here's the discussion so far:
Here's the discussion so far:
KurtV said:One thought on regional differences as regards possible stone and landscape damage caused by salt. The amount of rainfall may be a factor here. Dallas, where I think TPG hails from, gets somewhere around 33 inches of rain a year. The Gulf Coast, on the other hand, gets about twice that much rain. The use of softer stone in the Dallas area (if that's true) along with relatively low rainfall (though 30+ inches of rain is hardly arid) and high heat may result in more problems there than in some other areas. Likewise, potential salt damage to plants must be ameliorated by lots of rainfall flushing the salt away.
Waterbear said:Florida is a bit unique in climate since in the winter it's actually considered to be high desert (This information came from an Everglades Park Ranger who did educational presentations on Florida's ecosystem) and we get practically NO rain and in the summer we get a lot of rain almost daily. Yet there have not been reports of damage to stonework here in FL that I have ever heard about nor does there seem to be a lot of salt damage to plants in the winter (and in most parts of the state pools are open year round and in use. I live in the extreme northern part of the state and have about a 10 month swim season with the use of my heatpump.
KurtV said:According to this website Jacksonville gets 3.3, 2.35, 2.45, 3.39, and 2.59 inches of rain in October, November, December, January, and February respectively. Miami is 4.53, 3.32, 1.98, 2.44, and 2.14 over the same months. Pensacola is much wetter than either of those in the winter. Dallas, on the other hand, has similar rainfall in the winter but is much drier in the summer.
Ft. Meyers, which is closer to the area your park ranger is probably speaking of, does look a bit drier in the winter than the Atlantic and northern Gulf Coasts.
It's just a top-of-the-head theory, but I think these rainfall figures bolster rather than buck it.
Edit: Arizona is much, much drier than Dallas. I wonder if builders and owners are seeing the same kind of damage there on salt pools that TPG and others have noticed in Dallas.
thepoolguy said:KurtV: I think you're on to something. Arizona is having the same problems we're experiencing here in TX. Look at the 2 articles in Pool & Spa News; "Questions Arise About Salt Cholrine Generators" & "Coping With Salt" and most of the builders who have significant stone damage are in those two regions. I think another contributing factor is winter freezes. Here in TX, and I bet in AZ, we don't shut our pools down. We just let the freeze guard kick the pumps on. That includes the water feature pumps. And even if the water features are just a line off the main pump, we at least open them part way so the line won't freeze. That allows the water to aerate, settle on the stone, begin to soak in and then freeze and shatter the stone from the inside out. Your point about the rainfall slacking off in the summer here and in AZ would allow that splash out from pool use to soak in undisturbed and undilluted by rain, build up and reach that recrystallization point. Then, in the areas of the country where they don't get too many freezes and get lots of summer rain, they'd see a lot less of that kind of damage. Then, too, in the north, where they winterize their pools, they wouldn't suffer the splash out problems we do in winter, and they would more than likely get more summer rain than Texas or Arizona.
Your theory may just prove to be the answer to why it is a regional issue. Kudos!
chem geek said:This website has interesting information about various types of stones. Their bead test for water absorption has a scale that is measured in seconds which is inconsistent with what I've been told from other stone people who consider medium absorption in minutes, but it's still a useful guide to a variety of stone types and typical pros/cons (though nothing about salt so not of direct use here).
This website shows the annual evaporation rate in different areas of the country. This website shows annual precipitation, though precipitation in the summer is what is most relevant since that is when the evaporation rates are highest. This website (do a "Quick Search" of "Lower 48 States" "Precipitation" click Continue and select "Mean Total Precipitation" and click Continue) shows not only the annual, but the monthly precipitation (historical) in a map of the U.S.
I would expect that areas with the highest evaporation combined with the lowest summer rainfall would be most at risk to salt/stone issues. Combine that with softer (more absorbant) stones and perhaps we will see a trend here.
Poolsean said:Good point Kurt. The amount of rainfall will help rinse off salt residue and probably extends stone life moreso than other locations. I do agree with Waterbear too. I have not been involved with any corrosion, deck or stone issues that could have been contributed to salt. I've responded many times that I think we're blessed to live in a state that does get frequent rainfalls and perhaps that's why less or no problems in Florida, or other locations with similar weather patterns.
There have been some reports of similar type damage to limestone in Arizona too. I was up in Spokane, WA and a dealer up there had problems with aluminum automatic pool cover rails being affected by salt pools.
Palm Desert, similar conditions to Arizona, where they're also using flagstone/limestone, are not indicating any problems with salt systems.
That's why I try to point out that this is more product specific and can vary from location to location, and really dependent on the quality of the particular stone. It's not easy to single out specific products and say, "avoid using _____ with salt systems". If I say you can use marble, but there's a cheap version of stone that can still be "considered marble", who do you hold accountable when it crumbles? I know there's flagstone used throughout Florida that are not having problems. NONE at all.
How do I make a blanket statement that flagstone cannot be used? Or do you want manufacturers to state, "Flagstone cannot be used in ZZZZ city, if mined from XXX quarry"...
or "Do not use handrails of XXX grade stainless steel made by YYYYY, because of possible corrosion".
or "UPDATE...you can now use flagstone from AAAA as they have changed their supplier and is now acceptable for use."
Does this sound even remotely reasonable?
Can you imagine Ford posting every imaginable warning in the owners manual that you SHOULDN'T DO with their vehicles?
"DO NOT drive in rapidly moving water in Central Texas while it is raining EVERYDAY the last two months"
"DO NOT race Chevys....you'll get your doors blown off!"
Who would ever buy a Ford?
thepoolguy said:If you look at a list of the ten rainiest cities in the US, it makes an arc from Louisiana to Florida, mostly along or near the coast. That explains why you Southeast and Gulf Coast folks keep saying things about never seeing damage to sea walls and such and I remember the craggy, salt weathered seawalls of rain deprived Southern California and was wondering what you were all talking about. Boy, the more you think about it, the more sense this thing makes.
Now the only salt issues left to worry about are metal corrosion and the environmental impacts.
One thing that really troubles me, though. I can't believe that PoolSean and ThePoolGuy are both Chevy men.
A deeply troubling development.