Can one patch a concrete pool with water still in it?

Question

We live in N Texas and are under drought conditions and water restrictions, so draining is not an option. I have noticed rust stains [small but worrisome] on the bottom. No it is not algae or anything of that nature, and I have scrubbed them off only to have them come back in a few days. Is there a patching compound that can be used under water to shore these areas up?

Answer 1

I want to clarify, that you're not asking about a leak to patch, but a stain to cover. If so, what's happening to you, will only be affecting the appearance and not the structure of the shell.
If this is a plastered pool, not a painted one, what you're describing can be one of two things. Either a piece of tie wire from the rebar in the concrete is jutting up and close to the surface of the plaster and is leeching through or, when they shot the pool some oil from the compressor managed to get in the gunite mix. This usually takes a year to start showing as the oil is leeched into the plaster and looks an off grey colour.
I've seen both occur. If it's tie wire, it will be rust. There are only a couple solutions. What your are doing currently is one, but it will keep occurring. The other options, to do this right, are to drain and chip out the area, nip off the tie wire and replaster the area or to drain and paint( with epoxy pool paint). In either case, you won't have a colour match I'm afraid. The new plaster will be brighter or the epoxy paint won't match if you only paint the affected area. Painting the entire pool then becomes an option for looks.
If it's oil in the gunite mix, that doesn't bode well. I've never seen it successfully dealt with by removing the affected section. It is likely in most of the concrete and tends to pop up elsewhere. The only effective solution if this is indeed oil, is to paint the pool, requiring a drain. The oil can't leech through a quality epoxy paint.
There's two last possibilities for the stain cause to consider. Is there an overhanging tree, that's dropping buds? Some types of trees drop bits that when they settle on the bottom, will leave stains behind. They can look exactly like rust stains.
The other possibility being that someone is using a SOS pad, to remove tile marks. I've seen people do this, believe it or not. It will most certainly leave rust specks on the bottom, under the area the SOS pad was used. Stop using the pad and nothing more will show back up after it's brushed or a stain master is used. A stain master is a way to clean up some stains (small areas) underwater. It attaches to your pool pole and through syphon action, applies acid directly on the stain in a concentrated form. You say this is a recurring problem in one area though, so this will just clean it up but not cure your issue.
I've seen some people advocating the use of hydraulic cements. They don't cure under water. Fine in a damp area, but not totally submerged and it cures to a rough finnish and in a dark grey.
About the only thing you could use that does cure underwater is called two part marine epoxy. It's like kiddie Plasticine, that when kneaded together, can be used to stop underwater leaks or in this case, if spread thinly enough, could cover over the area if it's small. You won't get a colour match though. It sets in 30 minutes to an off white, almost light grey and will eventually chip off, requiring re doing. If it's rust causing the issue, it won't leech through the material.

Answer 2

1.fill the pool a little over the normal operating level 2.with the pump off and the water still use some dye(i use the phenol red ph solution from the test kit but you will have to buy a new one after you use it for this test)or food color look inside the skimmer mouth where the plastic and concrete come together squirt a little dye around this area being careful to not move the water much watch the dye if it gets drawn into the crack between the two parts you have a leak at that point slowly check around all skimmers if no leaks are found in or around the skimmers look in all areas at witch the water level stopped if nothing there remove the light from the niche and test were the cord goes into the conduit3.where the dye was pulled in get some pool putty (a@b epoxy) mix following directions and apply covering the crack retest with the dye and reapply putty until leak stops

Answer 3

I wanted to add; Many Pools today when they constructed they dig the hole and then use a material called "Pool-Crete" Once this sets they use a Rubber liner, usually blue, that is stretched out as they fill the pool with water to remove wrinkles. Then the edges are tuck out of sight with the final walkway and tiles are laid.
Yes it can be patched. First you have to find the leak, if this what you talking about. It helps if you have some SCUBA gear to stay under the water to work. I not remember, but, I believe you can use milk to find the leak or something that will cloud the water. Use something like those Plastic Ketchup and Mustard dispensers they have in Restaurants. Then you can slowly squirt out the solution the cloud the water around the area you suspect leaks. You will see your cloud seep into the area of the leak. Then you can circle the area with some type of marker and clean and patch. I not sure what they use. Call around to some Pool Dealers, I am sure there at least one that is honest and tell/sell you what you need to do this yourself. A hardware store my be another source for something that may work and be inexpensive. You would need a REAL Hardware store like a Mom-Pop thing, Ace Hardware and those places may not have anyone knowledgeable. They just tell you to go to a Pool Dealer.

Answer 4

"Hydraulic cement" is a patching agent that cures under water. It is most often used to seal leaks in basement foundation walls.
But...rust stains do not necessarily indicate a problem with the concrete. I'd leave everything alone until the time comes that the pool is drained and a good inspection can be done to determine the rust source.

Answer 5

I know the feeling.. but unfortunately.. IT CANNOT and should not be done with water still in it... It must be drained.. Yes I know.. water(dollars) down the drain... right now in N. TExas would be a good time to do it because you do not have the heat glaring down on the newly concreted inside of the pool and it is not freezing that also affects the setting of the cement they use on the inside of the pool.. but the pool has to be drained.

Answer 6

Hey.....I'm in Plano.....I really don't think you have anything to worry about. I know it has been dry, but that won't effect these gunite pools. My pool has been in for 13 years and I have had no problem with it. If you start loosing water drastically with no apparent source, then I'd be concerned. Good Luck!

Answer 7

They make epoxies that work under water, but the best options always require a good solid, clean, dry surface, anything else will just be a patch.

Answer 8

no because the concrete would not be able to dry if it was under water

Answer 9

You need Hydraplug.

Answer 10

they indeed do have that type ofmaterial but you need a qualified person to work with it and its exspensive