How do I get stains off the walls and bottom of my in ground concrete pool?

Thom L
by Thom L
My Pool
  12 answers
  • Joe Washington Joe Washington on Sep 03, 2011
    Thom, my first suggestion is to place some vitamin c tabs in a sock and place it on one of the stained areas. That will help determine if you have a problem with metals in your water and if that is the case the vitamin c will remove the stain. Take the result and a water sample to your local pool store and they will do a free water analysis and recommend the proper product to remove all of the stains and something to prevent a reoccurance. That's my easy, non technical answer.
  • sometimes as in the rust stains ,off the roof ,,,some material have traces of oxidizing agents
  • i meant ,,the concrete wall itself.in PuertoRico i built several,,,,using ,,shotkrete,,,concrete ,,just sprayed ,,,the intensive network of rebar and steel that goes together as net,,,,looks like a net,,except rebar,,,smetimes,,if pool has been empty at some point ,,has had a chance to break down(oxidize,,from pool chemicals) with the calcium and lime ine the concrete ,,to slightly bleed through,,,if you go to most older public pools ,,that civil engineers and or similar built you will see same affect,,,but Joe Washinton`s approach sound ideal ,,,,,
  • Thom L Thom L on Sep 07, 2011
    Thanks for the answers, but I'm still hoping for more ideas.
  • What kind of stains are you talking about? Most cement swimming pools are painted and once stained require new paint. But let us know what your seeing and we can help you a bit more on this subject.
  • Harold M Harold M on Sep 08, 2011
    I've seen cases where they were stained so bad a pool company had to re marcite it (think thats what its called). Don't know your money situation, but you might want to consider a pool remodel. I have a friend in Sarasota thats been in the pool business 30+ years and does remodels all the time Problem with paint, like anything else the stain will eventually come back unless you find the source
  • Thom L Thom L on Sep 08, 2011
    Thanks for your response. The pool was not painted, it was poured white; maybe it's not concrete
  • Thom L Thom L on Sep 08, 2011
    Thanks for the answers, but I'm still hoping for more ideas.
  • Joe Washington Joe Washington on Sep 09, 2011
    Thom, more than likely you have a plaster finish on your pool. Trust me, I've been down that road. Go to a pool store, Leslies is pretty good. Take a water sample and describe the stains. Removal will require a chemical treatment and it will take a few days to show results but it is effective.
  • Stains on a plaster wall pool can oftentimes become impossible to remove. If the pool has not been painted, the stain can be caused by a few things. As you have not described what the stain looks like I will make a few assumptions. Rust stain. This can be caused by a few things. But both are from metal. When troweling the walls to complete the finish if the contractor failed to use stainless steel trowels little specks of metal are broken off of the trowel which ends up in the finish. After a period of time these metal chips of sorts begin to rust and cause stain lines down the side of the wall or pool area. Still another reason for a rust stain is that the rebar used to construct the pool has become wet due to poor construction and failure of the plaster coating on the wall to keep the moisture away from it. As moisture hits the rebar, or even the wire mesh within the cement it too begins to rust and this rust begins to seep out of very tiny cracks on the surface of the plaster coat. In any case you can clean this rust by using any good quality rust removing chemical purchased over the counter. But this is only a temporary fix. You must find out what is causing this rust and correct it, or its only going to come back. Now if the stains your speaking of is sort of a white colored line that has begun to develop on the walls. That is a sign that water is effecting the plaster coating on the walls of the pool. then I would have the water checked first as using to much chemicals or in some cases not enough can cause all sorts of ugly things to happen not just to pool, but to filters, and other attachments connected to the pool that sees the same water.
  • there are plenty of stain removal methods - a citric acid removal, sequestering agent and filter aid is usually the best way if it's organic/metals. if its the surface itself discoloring you may need to acid wash the pool and may need a refinish but noone can determine that until A) you bring the water into a place to have it tested for metal content (iron, copper, manganese B) do the "test" to see what the dicoloration may be caused from: place a vitaminC tablet on one spot and a chlorine tablet on another for just a few minutes, see if either one lightens the stain. that will help detemine what its from. C) pay a compnay to come evaluate it D) try a CuLator bag in the skimmer for a few weeks and see what color the material inside turns, it will indicate what metals you have an help pull them out of the water. Personally i would try the test yourself first and see what happens.