Has anyone added massive amounts of natural stone to an existing pool?

KeysNole

In The Industry
May 7, 2016
27
Ft. Lauderdale, FL
We have a standard 15' x 30' in South Florida. No plans to be found. We are planning to add a significant (24 tons plus) of natural stone to the 15' side of the pool. This will be engineered and properly created, but I was looking to see if anyone had experience with a similar project.

We will cut into our pool wall to essentially add 5' of length to our existing pool. Helical piles and rebar would hold the new structure. Gunite shot in. Then tons of rocks. I know it has been done before...looking for any first hand experience or recommendations.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
46,713
Tallahassee, FL
Why are you doing this? Adding a water fall to it?

I would make sure none of the stone is in the water. Most of the pools I have seen with the stone in the water has problems with algae or calcium lines on them.
 

Jimrahbe

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TFP Expert
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Jul 7, 2014
19,130
Bedford, TX
Nole,

There is a very fine line between a great looking water fall and a big pile of rocks... :mrgreen:

I too would not have any rocks in the pool water.

Good luck..

Jim R.
 

YippeeSkippy

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LifeTime Supporter
Jan 17, 2012
14,582
Evans, Georgia
I find the addition of random rock piles look out of place in areas where they're not natural. Perhaps being in FL an elegant tiled water feature would fit in better?

Search here at TFP for efflourescence and you'll see pictures.

Maddie
 
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KeysNole

In The Industry
May 7, 2016
27
Ft. Lauderdale, FL
This reminds me of the costa Rica episode of Lucas Lagoons . .. is that what you are thinking?
Not quite on that scale, but that job was right down the street from me. Similar though.

We are aware that the rocks can affect water chemistry, but find it to be a small price to pay to get what we want.
 
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Sollace

Gold Supporter
Aug 16, 2020
212
Byran TX
If you can't find your answers here, you might look at pond builds. The reason I say that is we talked to a couple that had a pond and stream in their backyard. The rocks used attracted toads/frogs (sorry can't tell them apart). They had frogs everywhere. And this was ages ago so details escape me. I'm thinking the rocks the pond builder used were limestone. ?? They had to be replaced with something else so the frogs wouldn't party.
 

Dirk

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TFP Guide
Nov 12, 2017
6,855
Central California
With respect? If I were you... I'd listen to what folks are politely telling you. I think you're underestimating the water chemistry issue. The novelty of the underwater rocks will fade, the water issues will not. They'll be forever.

Here's a zany alternative, that will probably be much cheaper and solve for the chemistry. Install all the rock you want, but above the waterline. Then have the plaster/pebble installer shoot a second color of plaster/pebble, matched to your stone, just in the portion beneath your rocks. Except for a very calm day, the illusion will be pretty darn close, I'll bet. I think they could even vary the edge to simulate the shape of rocks, it wouldn't have to be a straight line. I've seen two-tone Baja ledge pools, this would just be a variation of that. Call me crazy, just not late for dinner. 🤪
 
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KeysNole

In The Industry
May 7, 2016
27
Ft. Lauderdale, FL
With respect? If I were you... I'd listen to what folks are politely telling you. I think you're underestimating the water chemistry issue. The novelty of the underwater rocks will fade, the water issues will not. They'll be forever.

Here's a zany alternative, that will probably be much cheaper and solve for the chemistry. Install all the rock you want, but above the waterline. Then have the plaster/pebble installer shoot a second color of plaster/pebble, matched to your stone, just in the portion beneath your rocks. Except for a very calm day, the illusion will be pretty darn close, I'll bet. I think they could even vary the edge to simulate the shape of rocks, it wouldn't have to be a straight line. I've seen two-tone Baja ledge pools, this would just be a variation of that. Call me crazy, just not late for dinner. 🤪
I don't disagree...but looking through this website there aren't many jobs like we are looking to create...and on the natural stone jobs we have come across, there wasn't much in the way of complaints.
 

Dirk

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TFP Guide
Nov 12, 2017
6,855
Central California
What types of chemistry issues can they cause?
I can think of a few, both how the rocks will affect the water, and how the water will affect the rocks.

- Any rock too near to, or entering, the water that gets exposed to splashes above the waterline will develop efflorescence. That white chalky deposit. It takes acid and muscle to get it off of smooth, glazed waterline tiles. Or bead blasting. I expect it would be near impossible to clean it out of the tiny crevices and pits in natural rocks. Eventually the rocks at the water line will be discolored permanently.

- If a pool develops algae, that algae can hide in a pool light, the weir door, a ladder, under the main drain, etc. making it very difficult to irradicate, even during a SLAM. You have to disassemble those things and scrub them clean. Can you imagine algae hiding in all the cracks and crevices of rocks, which are permanently adhered underwater. How could you possibly get that cleaned up?! Drain the pool and let it dry out for days or weeks? I'm not even sure that would work.

- You can forget about regularly brushing a rock wall, which can make it more susceptible to an algae outbreak.

- And there must be a way, but I cannot picture how you make a vertical wall of rocks water tight. I guess you plaster behind them, then set them? There would have to be voids, right? Otherwise known as algae caves. There will be no scrubbing of those, even if you were in dive gear. Those voids will be inaccessible. Maybe they're set in such a way that the backsides are totally encased in plaster, and so no voids? That would have to done perfectly.

- I would think a wall of rocks will play havoc with circulation, as it will be a giant speed brake of sorts.

I'm liking my crazy idea above more and more...
 
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Dirk

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TFP Guide
Nov 12, 2017
6,855
Central California
but looking through this website there aren't many jobs like we are looking to create...
Could that be because it's not workable?

Just to be clear, all my comments are pure speculation. I have no direct experience with what you are shooting for (other than removing the efflorescence. That I can back up.) So my apologies if I'm being a wet rag. I prefer to think of it as a "devil's advocate" dealio, so you can think this all through.
 

KeysNole

In The Industry
May 7, 2016
27
Ft. Lauderdale, FL
Dirk, everything you say makes sense and may be true. On the other hand, people are spending hundreds of thousands of dollars to have these problems. There was a member on this forum who addressed his natural stone and said his pool needed "a few glugs of acid everyday."

In terms of waterproofing, many of these jobs have gunite walls built behind them, then are back filled with concrete. The algae concerns are valid.

Lucas Congdon is probably the most famous person in the country who builds these types of projects. He is back logged for two years. So he's either mastered the water chemistry or leaving a trail of angry customers.
 

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Rich D

Bronze Supporter
Aug 3, 2018
918
MA
Are those links supposed to be showing rock pools with problems? All I am seeing is just pictures of beautiful pools with rocks.

I can think of a few, both how the rocks will affect the water, and how the water will affect the rocks.
Hmmm... I am only 3 years in with my submerged boulders and Boulder wall and have none of theses issues you speak of. I have zero efflorescence on the rocks but do have it from my coping and tile grout. I have seen a little green growing on 1 of the rocks in the Grotto but I just sprayed it with a heavy bleach concentration and it disappeared with no scrubbing. I would never build another pool without natural rocks blended in to the Build to soften the commercialized look of a pool. But that's just me...... ¯\_(ツ)_/¯
 
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Dirk

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TFP Guide
Nov 12, 2017
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Central California
Are those links supposed to be showing rock pools with problems? All I am seeing is just pictures of beautiful pools with rocks.
No, sorry, confusing. I was contradicting myself (on purpose), wanting to be fair. I googled for the type of pool the OP was looking for, and found plenty. The OP mentioned that they didn't find much in the way of that type of pool on TFP, and I quipped "Maybe cause they don't work." but obviously they are out there and somebody knows how to build them, and lots of folks (some number, anyway) have them. And I agree, some of them are amazing looking. I think some can get a bit gaudy, when they're overdone, or are in a setting or yard that doesn't support the look and structure, but others look very close to a natural element, they look as little like a swimming pool as possible and more like a pond, and those are very cool.

Again, don't mean to come off like "No way. You can't/shouldn't do that!" but rather "Just know what you're getting in to." Not that I know that (never having had a pool like that). You're more the expert than the rest of us nay-sayers...

I'm projecting and I'm lazy. So my point of view is skewed. I don't want to make things any harder on myself than necessary, so wouldn't want a pool like that. Not being able to walk all the way around it, to enjoy that aspect, or to maintain it, is not for me. But if the OP is willing to trade off the potential maintenance tasks and risks for the payoff of that type of pool... coolio!

We teach/preach here that if you maintain TFP guidelines you'll never have algae. And up to a few months ago I was the head cheer leader for that premise. Perfect water since day one, not a hint of algae. TFP rocks! But I got into a hot week and had a big swim party and then got a little careless and my FC just barely dipped below my minimum FC. For about a day maybe. Boom. Algae! (Which actually proves the premise!) I didn't have to slam. If was just a tinge on one section of wall (the one that gets the sun). I goosed the FC a few points and brushed and brushed and I haven't seen it since. CC is 0. I think I got away with it. But had that been a rock wall, the brushing wouldn't have worked and that little bout could have turned into a full-blown bloom. So that's where I'm coming from. If the OP maintains perfect TFP water, then maybe they'll never have an algae problem, but if they slip, their algae problem could get uglier than it would in a "non-rock" pool. The efflorescence issue is separate. I'm starting to see it now in my pool. My CH is dead on for my pool, I'm compulsive about CH, but I'm getting a tinge of efflorescence anyway. I believe that to be from evaporation, and not a CH maintenance issue, and seems to be inevitable in my pool (The previous owners let it get out of control. Took bead blasting to get it off.). So I do think that's a real issue for rock near the water. But again, you have more experience than I with the rock and efflorescence.

Just opining, take it or leave it.
 
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Dirk

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TFP Guide
Nov 12, 2017
6,855
Central California
Heres a cool page:
To me, some of these types of "lagoon" pools look barely like a pool and are done so well and fit so perfectly into the surrounding background that they create an amazing, relaxing experience. Others (to me) just look like a residential swimming pool with a bunch of giant, out of place boulders piled up next to it...