Acid Wash, Re-Plaster or something else?

[patplh]

We've been the owners of our pool since 2009, but it was built in 2000. Judging from the stains from when we moved it, I don't think it was acid washed or replastered prior to 2009.
Today was our pool closing day, so in an attempt to be helpful, I started draining the pool, but then I got distracted by work and forgot to stop it until it was more than 6 inches under the returns on the deep end (and more than a foot under the returns in the shallow. I pretty much drained 3 ft of water from our kidney shaped pool. I've always wanted to acid wash the stains, but never did b/c i can't bring myself to drain the pool, but here we are. I called up the company that closes our pool and explained that I may want to do an acid wash. He explained that it would rough up the surface and I might want to consider a re-plaster given the age of the pool. He's coming by tomorrow to check it out and make a recommendation.
I should also mention that i think our Calcium levels have been low in the pool when we first moved in and I start using the TFT100 kit. I added about 40lbs of CaCl pellets to bring it up to normal levels.
Below are some pictures of the pool. Can you make a recommendation? I'm leaning towards a replaster so we can start fresh, but also not sure of the costs .. I was told acid wash is $875 and re-plaster would be in the thousands.. this was before he saw the pool, so I'm guessing the # will change when he sees the size. Also wondering if I should take the time now to enhance the pool, maybe consider adding special features to the plaster? blue/speckles? maybe start using SWG instead of straight Chlorine. It's not like we hit the lottery, but I'd like to do all the work at once and not worry about it later..
NOTE:
Image1b is a full pic of the pool - the grayish areas are the stains
Image4b shows you the steps, which are also grayish and brownish
Image5b is a close up picture of the gunite
Image7b is a rust stain from the kids leaving a metal water pail in the pool. I tried to scrape it off with a metal spatula. the rust stainr was darker, you can see the white discoloration is where i scraped it by hand.
Image 8 is the deep end of the pool, but shows some areas where it seems like a trichlor puck or something dropped into the pook and left there and bleached the area?
Aside from the rust stain, all the other stains were there before we were owners.

Thanks so much for any advice you might have!!
Love TFP!!

 

[kimkats]

What does the plaster feel like?

Have you tried vitamin C on the rust stain? How about on the rest of the plaster?

It does look like the plaster liked the chlorine puck.......I wonder...................We will get into that once you answer the above questions.

Kim

 

[Foxy]

I have a pool built in 2000 also and nothing was done to it since then, until we moved in 2 years ago. We drained it, had too, cause the water was terrible. Our plaster is standard white and was stained aqua blue, so we decided to acid wash since it was empty. We did the acid wash ourselves, it was a lot easier than we thought and not too pricey for materials. It did remove the blue staining we had, but we didn't have coloring like your pics show. Unfortunately, I'm not able to find the pics we took back then. We did have a pool company come out to give an opinion on the condition of our plaster, we have tiny cracks showing, mostly on the flat surfaces like steps, benches. We were advised not to drain it again otherwise we might cause the plaster to crack more and start flaking off, expansion and contraction as it dries and wets, that was 2yrs ago and it hasn't got any worse. We have decided to re-plaster soon and do a remodel to update the pool, our deck is a mess also, so we just started getting quotes recently and deciding what all to do. Renovation in Henderson NV

You can try a small spot with muriatic acid and a scrubber yourself to see how much comes off, just be careful.

 

[patplh]

Hi Foxy, I bought Muriatic Acid from Ace Hardware a few years ago to help get rid of the white deposits on the rock wall.. visible in our first pic. I'll see if I have any left and try that out too.. Thanks!

MORE Questions for the TFP community since you guys know more about pool construction than I do
Do you have any suggestions about Efflorescence? I posted about it a few years ago - http://www.troublefreepool.com/threads/32927-what-is-this-white-stuff?p=275349#post275349
I tried Muriatic acid, but it didn't do much to it.. so twice a summer I chip away at it with a metal spatula. If there's a way to resolve this long term, I'd love to hear it. You can see from the first pic that the wall is still wet b/c we had a rainy day, and the water is seeping down the rock wall into the pool. Is that normal? should I have a barrier to prevent that which would prevent the white deposits?

Thanks again!!

- - - Updated - - -

Hi Kim, I thought I responded this earlier morning, but I must not have posted it.
The plaster feels smooth. I've never thought that it was rough. I've also never tried Vitamin C. I'll try that tonight.
I had "acid wash" ingrained in my head from a landscaper commenting on the staining in the pool.. so that's what I thought I needed, but after reading the forums about acid wash, there are probably alternatives I should try first.

Can you also see my previous response to Foxy? We also have an efflorescence (i think) issue with our rocks that I'd love to get your opinion on too.
Thanks!
Patty

What does the plaster feel like?

Have you tried vitamin C on the rust stain? How about on the rest of the plaster?

It does look like the plaster liked the chlorine puck.......I wonder...................We will get into that once you answer the above questions.

Kim

 

[kimkats]

I have looked at your other thread..................something is sure leaching out of the rock..........calcium? Does the stone/rock appear to be eroding over time? How about the grout of whatever is around the stone? How is it holding up?

Answer these questions and let me think about it...............I will get back with you as I have a couple of thoughts. Just beware I tend to throw out wild ideas just to see what sticks! LOL

Kim

 

[patplh]

Hi Kim, the stone and rock seem fine, the grout has loosen in some areas at the top of the rock wall - to the point where 1 rock is completely loose, but there is no visible loosening near the pool.
Thanks again.

 

[kimkats]

okay................so the grout has lessened.........so that means that it is "going away" or being washed out slowly............think like water for a minute here..............as water comes down from the area of lose grout would it end up where the white stuff is? I would even pour some water on the rocks so you can watch it and see where it does.

I am cooking some ideas now................let me know what you find/think after what I just said........

Kim

 

[ummgood]

Honestly I would be tempted to try the cheapest do-it-yourself solution first. Then if you still aren't happy then budget for the bigger remodel. That is just me. It can't hurt anything to try the muratic acid approach on the steps etc... and see how it turns out. You might get a few years on that before you really have to spend the money.

Oh and if your MA is a few years old then you might need new stuff I am sure it probably has lost its strength.

 

[patplh]

OK, we're going to try some Muriatic Acid and Vitamin C this weekend.
Is it a problem that the pool water level is low. Is it bad for the plaster to be exposed to the air? reminder: i'm in MA and it's getting cold here.. I will still plan to close the pool, but it won't be until mid-october probably.

Also, regarding Kim's question - you can kinda see how the water leaks through from my first picture above and in the new pictures i've attached. It's rained a bit here and there's still residual water that you can see dripping down the plaster. But I should mention that the area where the rock is loose is not near the pool.. I added more pics below and it's on the far right of the full pool pic and not even in the actual picture.

 

[kimkats]

Well that blows one idea out then...............

I am thinking it is the grout that is being leached out and causing the white stuff. Whatever the grout is made of is not happy being wet.

I know CLR works great on calcium in tubs and such BUT I do NOT think it is something that should get into a pool.

Have you tried the muratic acid? I was reading your other post from long ago. Did you look into what this person said?

"Eventually, but this is many years, it will weaken the cement. It is, as Jason said, effervescence, a process where the calcium in the cement or mortar is brought to the surface by the weeping water. Cements have a lot of calcium in them.

To stop it from recurring, you will need a drainage system put in to capture the run off water from the hill and carry it away from the wall. The back of the wall should have been sealed, not unlike the foundation of a basement.

The remove what is showing now, you will need a bucket (non-metallic!), an acid resistant scrub brush (shower brushes work well), rubber gloves, goggles, a hose, and diluted muriatic acid (3 parts water and 1 part acid), some baking soda and likely some washing soda too.

Scrub the white stuff with the brush and acid water mix. Rinse well. Repeat as needed. When its removed, rinse/scrub the area with a water and baking soda mix to neutralize. Expect fizzing.

Pour the rest in the pool and add baking soda and washing soda as needed to rebalance the pool water.

Scott"


This sounds just like I was thinking. Stop the water from moving through the rock wall. That will stop the leeching of the white stuff.

Kim

 

[Foxy]

We have very hard tap water here, so we get white crusty build up on everything, even the faucets in the house get it, but I don't know if it's the same thing that is going on in your pool. We had a hard water stain, ring around the pool on the tiles, when we bought the house, because the pool had been sitting unattended. We used diluted muriatic acid and a scrub brush to get it off, tried a pumice stone also which works, but is more work and we were going through the pumice stones quickly. Every pool that I've seen locally with a rock feature has really bad build up, but it's all where the water touches or splashes, so looks different than your white stuff since your have it where the pool water isn't touching the rocks (I think).

 

[patplh]

Thanks again for the responses.. I'm off to the store to pick up some vit c tablets and muriatic acid.
The pool company came by on friday and said that we could do a light acid wash, but after that we'd probably need a replaster.
Acid wash quoted was $875. Replaster quoted was $7500.
The other thing he noted was that there was rust from one of the returns. it's been there since we moved in, i don't recall it getting worse, but he says it's from a crack which is getting the rebar wet and causing rust to come into the pool. any ideas on how to fix that? if we replaster, they can fix it then, i assume.
He also mentioned that we'll still have to fill the pool after we wash it this season so that the groundwater does try to raise the pool.. crazy, never thought that was a possibility.
Any thoughts on the quotes? We're probbaly going to try and clear up the stains ourselves this season.. and then plan to replaster in a few years.

 

[Marlahoutex]

I don't really know about fixing cracks, but I've heard a lot on this forum about epoxy being used to fill holes. So perhaps that's an option. I'm sure someone who knows way more will come along to give you better info.

 

[kimkats]

No idea on the quotes but I do know that any time I am looking to pay for work I get at least 3 prices if not as many as 5 if possible. I have found the prices and quality of work quite a bit in most trades.

The rust stain--------we have seen where a small piece of rebar tie was poking out and caused a small rust stain. You can chip it out and put a patch over it. Let us know and someone should be able to help with what to patch with.

I like the idea of working on the stains yourself to be followed by a replaster. That gives you time to save your pennies!

Kim

 

[patplh]

OK, so I tried Vitamin C and Muriatic Acid. For Vitamin C, i wet the area and then rubbed the area with the vitamin C tablet. For Muriatic Acid, I mixed 6 oz of acid with 1/2 gallon of water (bottle said to mix 12 oz with 1 gallon for brightening concrete, etc)
Images explained>
1. The rust stain after Vit C appears to have gotten darker.
2. I put dropped a tablet into the water - bottom stair is still about 1/2 inch under water and that definitely cleared some staining
3. I poured the diluted Muriatic acid and it removed some stains, but i was surprised by what appears to be a cracked appearance of the plaster afterwards. Is this normal? I don't even know what color the plaster should be. Am I eating away too much of it? it bubbles in certain areas when I poured it on. thinking maybe I didn't mix it enough?
4. You can see how the stains have gone away from the side of the stairs.
What should I do next? FYI, i won't be able to tackle it until Columbus Day.

 

[kimkats]

What does the "cracked" are feel like? Can you lift any of it with your finger nail?

How long did you leave the Vit. C on the rust stain?

Kim

 

[patplh]

Hi Kim - I meant to say that it looks cracked, but it still feels as smooth as an area that i haven't touched with the acid.
I took some more pictures this morning and the color has definitely lightened. The first is a close up of what i meant when I said "cracked". I think the pics make it seem brighter than it really is, but you can see from the pic of the stairs that the acid that dripped down clearly lightened the stain.
What would you recommend as next steps? If the first pic, which shows the crackling appearance (it's not really cracked) is OK, then I'm inclined to try to do it ourselves. Our pool water is full of algae, is the recommendation to clear the algae and them add acid to the pool .. or drain the entire pool and then scrub with acid quickly to not have issue with the groundwater pressure?
Also, what is the recommendation for doing the walls? I had a hard time making any sort of impact on the walls. The Acid didn't seem to do much - should I increase the concentration? Thanks again!!

What does the "cracked" are feel like? Can you lift any of it with your finger nail?

How long did you leave the Vit. C on the rust stain?

Kim

 

[patplh]

Also, i put another vit c tablet on the rust stain.. How long should I leave it there? It's been about 10 minutes with no change in color. I think my initial thought that it darkened wasn't accurate. When it dried, it was the same color as before, i think.

 

[kimkats]

I THINK the vit. c needs to be in the water to make it work. I am not sure.

For the stains............You can buy some cheap towels. Soak them in the MA/water and hang them on the walls so the towels hold the MA to the side.

I wonder if there are any youtubes or such for doing this? Might want to do a search..............I bet there is! (sorry to lazy to do it for you LOL)

I do NOT want to tell you what to do or how to do it just in case it messes you up LOL. Sorry

Kim

 

[patplh]

I don't really know about fixing cracks, but I've heard a lot on this forum about epoxy being used to fill holes. So perhaps that's an option. I'm sure someone who knows way more will come along to give you better info.

Thanks Marla - I'll check the forums a little bit more closely about cracks near lighting fixtures. Is there anyone in particular you think could chime in before i tackle this beast over the weekend? I might just send them a private message asking them to review my pictures.