This is the product I used on my own pool and it has held up great. I used the high gloss and it really made my flagstone look great...

Here is a link that might be useful: Sealer

We have a chlorine pool with flagstone but our town well water has an extremely high salt content. Slat build up is not uncommon where water sprinklers hit a surface regularly. That said, our water from the pool has not been kind to our Oklahoma flagstone.
We are going to clean ours as well to get up all the loose stuff but not sure how to clean up the rusty areas. The rings probably go too deep but the streaking is not all loose in some area. Just unsightly.

Salt pools are going out of favor because of the damage they do to natural stone. Consider converting to ozone + chlorine and remove the salt cell.

What should be out of style is Oklahoma Flagstone. It isn't a suitable coping.

A zinc anode will help with electrolysis related corrosion.

Proper chemistry will help reduce the calcium scaling.

Ozone has its own set of issues.

Scott

I agree with Scott my Tennessee Flagstone has no sign of damage from the salt and My pool is 5yrs old. The old test of hitting it with a hammer and if it pings it's ok for coping but if you hear a dull thud than don't use it has something to it. IMO

Wow, Where you been muddy? Welcome home!

Scott

I have been in the back looking in. You do such a good job with the questions I just don't need to comment...lol

Well, I can sure use the help. It's the start of my busy season!

Scott

ok our pool is only 5 years old this summer..the salt cell has been replaced among many other parts, the oklahoma flagstone scales like crazy and we can never keep the grout and the tile connnected because of the contracting the flagstone does with heat and cold...so called the pool company out and they did the hammer test(which Muddy above talks about...not sure if he agrees with that test??) and guess what?? they said not only does all our decking need to be replaced(1800 sq ft!!) but coping as well and pool resurfaced?? seriously?? I remodel houses for a business and trust me I know all about natural stone...i do NOT think these products were ever inteneded to be used around pools especially salt water ones...when asking this to pool builder they stare at you blankly and offer NO response!! I am sure its because they still sell it and do NOT tell the customers to steer clear away from it...so now what do i select?? I have stone everywhere...retaining walls etc..im so mad!

Salt has nothing to do with it.

Scott

Could it be your water chemistry that's causing the problem?

Before deciding on alternate/replacement materials, I would try to figure out why this happened in the first place - or you might be in the same position again. Some may say the culprit is the salt, while others cite alternate theories. Ask someone that doesn't think it's the salt what they think it could be and check it out. The pool needing to be resurfaced signals to me that it's not the salt, but rather something wrong with maintainence and water chemistry.

If it's truly the salt - the pool builders I interviewed said that the best choice for coping is brick or the old pre-cast concrete forms. Either choice might be a little out-dated when compared to natural stone, but at least nobody has had any corrosion problems!

@funinthesun1

Did the dupont sealer make your flagstone look any darker or did it change the color of it?

I am considering using the same dupont product. How large is yyour pool? 3 years later does it still bead up the salt water?

http://www.houzz.com/user/funinthesun1-gw I need some help. We are having a pool built. I live in Houston. We are not doing the saltwater. should I have my flagstone pressure washed and sealed before they start with the pebble sheen?

@funinthesun1 @swtsae Did the sealant change the color of the flagstone? We are having a light grey flagstone installed.

I have some kind of strange flagstone around my pool. It is very wavy and rippled looking. It is literally turning to dust on me. I do not think it has anything to do with the salt pool. It started two winters ago when it rained so much. We were not even using the pool. I sealed it with some stuff called Dek-O-Shield Plus. It worked great. For a month. Then the sealed surface started to debond from the junk stone beneath it. It looks like someone dumped a load of sand into my pool. I have to sweep off the decking around it.

Has anyone seen stone like this before? I don't think it is the right kind of stone of pool use. The installers made the comment that all the stone yards were out of stone and this was all they could get. I am about to be up on my 3 year warranty on the pool and am not sure what I can do about. My builder is very dismissive of it, but I think this was a substandard product installed on my pool. Im pretty good a keeping water chemistry in check so I don't think it is that either.

This is not natural stone. This Kool Deck. It's a coating put on to "green" concrete to create a textured look but mostly to resist heat to keep your deck cool. It comes in a few colors.

No. it is most definitely stone. I have used the leftovers to build edging for flower bed. It does kinda have that cool deck ripple texture though. I've never seen flagstone like it. nor has anyone at any of the stoneyards I took it too when trying match it.

Could you post photos of the flower bed edging?

I will stand on my determination of the material based on the previous photo posted. Reason is, I see a white, plastic control expansion joint on the patio. That indicates poured concrete. The "false" joint between the patio and the coping indicates it was poured as a monolithic pour and the joint was made with a mason tool to give the appearance of a separate stone with a profile nose on the inside of the pool.

The krinkly finish is Kool Deck.

In my 30+ years, I have only see a few Kool Deck finishes that have not peeled. It's all about timing when applying this material to provide a lasting finish. So when I see this finish in the present condition, I don't find it unusual to peel/delaminate from the substrate.

Hi we are having the same problem as all of these other pool customers; however, our deteriorating flagstone began 1-2 weeks after fill. Couple things, the pool company came to acid wash the coping bc mastic drops and boot prints were all over the top of the flagstone. We also have a salt pool but are baffled by this stone flaking off the large pieces when we haven’t even had the pool for a month. Please help. Any advice? Pool company is saying it is not defective coping…I’m at a loss and need some guidance. If @poolguynj has experience don’t hesitate to comment.

This is really interesting. Thanks for sharing!

There isn’t anything you can do about it. Flagstone is simply a sandstone. Some harder than others. Even with mine, Oklahoma Flagstone, some stones are harder than others as well as the worst ones were the ones that seemed to be the favorite gripping ones in certain locations so not all are affected. The very large piece that covers our grotto (waterfall) has a lot of flaking underneath. I’m sure it would be worse if it ran more often. The travertine we put on top of our grill island has held up perfectly compared. Real stone is great to use. Just be careful what type. I’ll never build another pool but if I did, I would stay away from a sandstone for coping.

@mandyloo81 also, Scott, the poolguyNJ passed away from cancer many yrs ago. He is truly missed.