Any Concerns Going to SWG W/ Unsealed Flagstone Coping?

Jump to latest Follow Reply
D

Duk

0
LifeTime Supporter
Jul 7, 2007
43
Katy, TX.
I'm seriously considering the installation of a Goldline Aqua Rite SWG. Are there any issues with a saltwater pool and unsealed flagstone for coping and on the deck edge?
Better to ask now, rather than later with an issue.
Thanks,
Larry
 
Results vary. It depends on how solid the flagstone is (which is difficult to determine in advance), how much water gets splashed up on the flagstone, how much rain you get, etc. The more salt that accumulates on the flagstone and the more porous the stone, the more likely you are to have trouble.

Problems aren't likely, but since the exact risk is difficult to determine, I would seal the flagstone before installing a SWG.
 
I also have flagstone at the waterline. In these cases is your flagstone sealed and are you having to reseal it annually. I am concerned about all of the damage I am reading about on the blogs from people who have converted to SWG. Some people claim no damage, others talk about the rapid corrosion of equipment and natural stone. I don't know how these owners maintained their water chemistry balance. My pool is almost 8 years old, and I have not experienced but minor errosion of the flagstone, no cracking and no corrosion issues. I don't want to initiate damage. What are your thoughts on the claimed damage?
Thanks,
Larry
PS: What would be a good installed price for a T-15 Goldline SWG and start-up?
 
There are a couple of well documented cases of dramatic stone damage, and there are also thousands of people who haven't had any problems at all. My interpretation is that the problems are due to the use of inferior stone, but it is impossible to say that for sure at this time.
 
I recently visited a family member who built a pool around the same time as me. He went salt, and I did not. I told him of problems I've read about with natural stone. He was giving me a hard time because of how easy his pool is to maintain. I said.."Yeah, but look at your stone...it feels like sand paper!". He said it wasn't, and he would prove it. He went to the side of his house to get a piece of the stone coping that was excess. He set it down with the other stone. Much to his surprise, he realized how much the stone had deteriorated. Not only in texture, but color as well. His stone is a dark gray, slate looking stone, and it is not sealed.

Bottom line, I think the reason no one says they have a problem is because it happens gradually over time and they just don't realize it. I have yet to find anyone who has their stone sealed from the start, so I don't know how much that really helps. I look forward to finding someone who does, because I would ultimately love to convert to salt.
 
HOw old is your pool and what kind of chlorine are you maintaining your pool with?

If Liquid, I would encourage you to take a water sample to your pool store and have the salinity tested. You would be surprised what the level of a bleach pool is after several years!

Assuming that you may have a significant amount of salt already in your pool, if you do not see any signs of damage, adding a salt system will not cause any additional damage. period.

Having said that, the only way a salt system may cause damage is due to improper operation of the system. Meaning, if you do not monitor the output setting of your salt system, it is easy to ignore it because "it's so easy to maintain". Quite frankly, your chlorine may be too high, and we find that the high chlorine will cause more damage to your flagstone (especially inferior quality stone) than the salt will.
 
It's all a matter of degree. In plaster pools after startup, you are already at roughly 500 ppm TDS from the calcium and bicarbonate added to the pool. As you use chlorine, the salt (sodium chloride) level rises. In a typical non-SWG pool using chlorinating liquid or bleach you'll have 1000-1500 ppm TDS assuming some amount of regular dilution. At 2 ppm FC per day, salt increases by 576 ppm in 6 months so over years without significant dilution it can build up.

So the differences we are talking about are a factor of 2 to 3 in terms of salt concentration in the typical non-SWG vs. SWG pools. To the extent that there is damage from salt recrystallization, it's not a binary thing but how long it takes to get roughly the same amount of wear. Also note that chlorine may cause some wear as can lower pH -- all depending on the type of stone.

So if you are using materials susceptible to wear from splash-out and evaporation cycles, then you might be increasing such wear by a factor of 2-3, all else equal (which it's not, usually). If something was going to degrade in 50 years, then having it wear in 17 years given everything else that occurs over that same period of time may not be a big deal. If you've got something that would normally last 10 years but degrades in 3, then that might be a bigger problem.

Pool water is a harsh environment so sensitive (absorbant) stone materials should be sealed, period. I don't have flagstone and don't have an SWG (and have had TDS levels in the 1000-1500 range), but have "simulated" flagstone using troweled concrete, but we have that sealed every year because I'll be Darn if I'm going to spend that kind of money again on a hardscape anytime soon! :shock:

Richard
 

Enjoying this content?

Support TFP with a donation.

Give Support
When I was doing my research a year and a half ago, one thing I came across talked about how the problem was occurring in Texas/Louisiana areas, but not really in other parts. Theories of rainfall issues and other weather patterns were speculated to be the reason for that...but nothing conclusive.

So, this may be a regional issue. California, Florida, N. Carolina, all may have different results. I have seen the problems first hand on 3 friends pools with salt, no sealer. I have chlorine, same age pool (w/ in a year), the same Oklahoma Wister coping, and no noticable roughing or discoloration of the stone surface.

Lastly, for what it is worth, Platinum pools (did not build my pool, but quoted), was no longer installing salt systems when I built my pool because they had been paying to replace stone work. A friend just got a quote from Perry Pools in Houston last week, they will do salt, but he recommended against it because of the problems he sees. The builder I used, is still using and recommending salt...so pick your answer.

I don't know anything about the chemistry and comparisons to liquid bleach, but I know what I have seen. At least in the greater Houston, TX area, it seems to be a problem.
 
There is no question that SWG salt levels can accelerate corrosion in some materials, but in those materials the exact same corrosion will still be happening anyway, without the added salt, just more slowly. It seems like the stone that is most commonly used in Texas these days breaks down much more quickly then the stone most commonly used in other areas. That means that it is going to fail on all of the pools it is used on, it will just take a couple more years.

There are kinds of stone that are essentially impervious to salt corrosion, ie there won't be any visible effect over the lifetime of the pool. There are other kinds of stone that can fail in months. The tricky thing is that it isn't always obvious which kind you have, unless it starts to fail. Adding extra salt to the water, speeds everything up a little, but it doesn't transform stone that is good for the lifetime of the pool into stone that fails quickly.

Sealing the stone will delay any corrosion that might happen fairly significantly, but it won't completely prevent it.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply