Leak in pool

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
Hi Everyone! First time posting here. I bought a house built in the 1980s a few months ago which came with a pool (likely of the same age). I didn't have much information to go on, so it's been a learning process. I've read a bunch of pool school which is super helpful (thanks!). I'm writing today to ask about pool putty. There is a jet/return in this area, and 3 other jets/returns in the main pool. One skimmer, and one "main drain" at the bottom of the pool. There are tiles at the water level going all around the pool, and there is a wall of tiles on the surface the waterfall runs down.

About the pool: I have been taking water samples to a local store, and on their printout it says the pool is "Marcite/Gunnite" and 20000 gallons. When I showed a picture to the pool store people, they said it was likely less, and their guess was 15k gal. It's in the ground in Central Florida. There is a separate, raised area with a small pool (about 6-12 inches deep) with a waterfall into the main pool area.

TL;DR- can pool putty survive being regularly in and out of water (wide temperature range, regularly going from wet to dry and back again) in the Florida sun and heat?

I noted repeated drops in my water level, and I kept filling it. I did the bucket test with the filter running, and it was positive upon recheck at 24 hours. So I definitely have a leak. Initially I assumed it was at the skimmer, because it looked like the water level dropped relatively quickly to that level then slowly dropped more (which I attributed to evaporation). I bought the dye test kit, and I checked my jets/returns (negative), the place where you connect the vacuum (don't know the technical term for this port, but anyway it was also negative), the light (negative), and the skimmer (surprise- negative!).

My next step was going to be to purchase some plugs for the jets/returns, but before I did that I noticed that there was water literally streaming out between two of the tiles near the waterfall. I'm going to call this the "bottom hole". Now, given the water is flowing INTO the pool from between the tiles, I know that's not the leak. But it's likely nearby, and the water is going through the ground and pushing out between the tiles. I suspected the small raised area with the waterfall has a leak somewhere, and it's flowing under the raised area and pushed through the tiles back into the pool.

I went to the pump/filter complex, and there is a PVC pipe labeled "waterfall" which I closed the valve on. The jet/return to the waterfall stopped running, and the waterfall stopped dripping water into the main pool. I left the pump running overnight, and the water level in the pool seems stable, and the water level in the small pool also seems stable. The water is no longer cascading through the tiles into the main pool. I have not yet leak tested the raised/small pool. What I did note, however, is that where the water normally flows from the small pool into the large pool, there are 4 tiles that the water runs over as it moves from the small pool to drop into the large pool. In the middle of the four tiles where the grout should be there is a hole ("top hole") which I plan to patch after leak testing the jet/return in the small pool. These four tiles are facing UP- they are not vertically oriented like all the rest in the pool. They are also normally subjected to severe conditions- they are immersed in pool water when the pump is running, and then they dry off and bake in the Florida sun when the pump is off. Can I close the top hole with pool putty, or do I need something else, or is there something more suitable for this spot?

Thank you for your help in advance, and thank you to all the forum folks for making learning about my pool so much easier!
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
20,287
Northern NJ
Welcome to TFP.

Pics of the areas you describe would really help us understand your situation better.

If you are missing grout then you should replace it with pool grout and not putty.
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
Ok, here goes:

This is a super close up of the water spurting out of the tiles.

. IMG01.jpg

Same picture with the arrows pointing at the water which is flowing from behind the tiles back into the pool.

IMG01-annotated.jpg

This is a a picture showing the waterfall, with the small leak. This should help give an idea to the relationship between the large pool, waterfall, and small pool (not able to be seen here). The water spurting out of the tiles can be seen to the right of the waterfall, though it's a little harder to see in this photo due to being zoomed out.
IMG2.jpg

This is a partial image of the small, raised pool with the four tiles over which the water flows to go from upper (small) pool to lower (large) pool:
Note- this image is being rotated by the website, and I can't figure out how to fix it.

IMG02b.jpg

Zoom up of the same tiles. The red line is the area with mostly eroded grout or just sand particles, and the space between the tiles is narrow so hard to see what's under it. The purple plus is the area where the grout is completely gone, and I can see there's a hole/empty space underneath. The black arrows again indicate direction of water flow.

IMG-03b.jpg

Again, I'm here because I'm new at this, but my (uneducated) guess is that the water is leaking down through the red/purple area and somehow flowing behind the tiles on the wall of the large pool, and spurting out between the tiles as noted above.

I was thinking about putting the pool putty on the red and purple areas to seal the apparent leak. However, I'm concerned if this is sufficient or the proper way to fix this. Do I need to pull up the tiles and fill in the empty space below with something like concrete? Something more drastic? Or can I get away with sealing the tiles with pool putty, or as ajw22 suggested, using pool grout? (Thanks ajw22!)

Thank you everyone for reading, and thanks for your help in advance!
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
Update: after doing all the above, I raised the water level to about 1/2 of the height of the skimmer and ran the pump overnight with the waterfall return blocked at the pump outlet (no water flowing into the small pool and thus no water running over the waterfall). There was no apparent drop in the water level, whereas previously it was noticeable pretty quickly. Next, it rained for the following 36 hours nearly straight and the pool is just about overflowing so can't say for sure anything about the leak, except I may have to drain some water tomorrow!
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
47,014
Tallahassee, FL
I love those tiles. They are so classic looking! I bet you can't even find them to buy any more which is a shame.

This is a great write up and the pics should help us help you solve your issues. @ajw22 should have some good ideas. He might even call in a couple of others to bounce ideas off of to make sure it is what you need to do. You are in great hands with him!

Kim:kim:
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
20,287
Northern NJ
Is the small pool a spa or is this a two level pool?

I think you are on the right track that water is getting into the wall and flowing out that lower hole. All the water is not flowing out the hole you see and leaking into areas outside the pool. You need to waterproof areas to keep the water from getting into the wall. I would not patch the areas water is flowing out from until you stop the water flow.

Regrouting the top of the waterfall would be my first step and see what effect that has.

I wrote about doing grout repair here...

 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
Small pool. No heat/chill, no extra jets. If I sit in it, nobody else can fit. If people sit on the coping everyone can play footsie together in the 8-12" deep water...
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
Ajw22- If only it was biggie enough to be a kiddie pool!

Kimkats- there's a reason I crop all the photos at or near the pool's edge :). I guess I could post one as the "before" for before and after. Its pretty wild and overgrown. Getting the pool stabilized is (one of) my 2019 projects, and the yard is ideally a 2020 project!
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
47,014
Tallahassee, FL
We have seen pools that you would think are ponds with all of the stuff growing around them AND in them so you don't have any worries of us judging you!! You do need to post before pics so we can cheer you along the way.

Yeah best to wait on the yard until it starts to cool down here in FL. It has been "sick hot" summer for sure! We have quite a bit of catching up on property work here as we have put it off due to the heat this summer.

Kim:kim:
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
EZ Patch 4 is on the way in the mail, and I bought a manual grout saw. Also got home today before dark and found a few more suspicious places that I plan to grout saw then fill in with fresh grout, all in the "smaller than a kiddie pool" pool

waterfall-additional-hole-01.jpg
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
ughhhh hairline cracks??? Now that you mention it, that makes sense since it needs to be totally waterproof. I may need more than the 1 lb grout package I purchased!
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
Ok, time for an update. Did the grout replacement today, looks like:
1571358117808.png

Also did several other areas that didn't seem like a great grout seal. Now waiting 24 hours for it to set/dry, and fingers crossed she's watertight again!
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
test failed- water still spurting out from the grout at pictured above, but I found another gigantic hole, so will patch that and try again! Also did leak test on the return, and was negative so looks like the leak is restricted to the upper pool, inner aspect including the waterfall part.
 
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Reactions: kimkats

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
The gigantic hole was underneath a ledge formed by the horizontal tiles. When I put the (manual) grout saw to the area, it fell apart like a hot knife through butter. I scraped all that away, then re-patched with grout.

As an aside, I bought the 1 lb EZ Patch 4 not-fast-set, and I've used almost all of it. For anyone reading this who has a pool leak, I'd say to get the 3 lb size at a minimum. I thought "Oh I just have this one little area" and I only need just a little bit of grout. Wrong!
 

FlaPoolGuy

Gold Supporter
Oct 5, 2019
80
Florida
It was a little bigger than a pinhole when I started. I think what happened was when I was using the grout saw nearby, the loose grout fell into the area and made the hole look smaller. After the water started shooting out of the grout (as pictured above) again, I stuck my finger into the return in the small pool. Some small amount of remaining water fell over the waterfall, and then stopped. I then waited a minute or two for the water to stop swirling. At that point I had the small pool filled to the edge, and I started shooting the dye tester I had at any aberration in the surface of the grout until I found it. It was sucking in the dye SUPER fast. Next I removed my finger from the return and quickly blocked the return at the pump so no more water could get in or out of the small pool. This had the effect of locking the existing water into small pool. After leaving it to stagnate overnight, the water's level did not lower any further than the hole I found, so I assumed there were no holes below the level of the one I just discovered. Here's the visual:

img-03c.jpg