newbie plaster question

[poolquestions4u]

Hey yall, here's my story...

Bought my first house last September with an IG pool. Pool is gunite, 18k gallons, chlorine, Nature 2 express, cartridge filters, no heater, no spa. The person I purchased the house from recommended the local pool shop down the road to test my water. He told me that he had simply just gone to them ever since he had the pool put in. I'm not sure the exact age of the pool, the house is 1999 and I think the pool was put in a few years after so maybe it's about 7 years old. The pool was in perfect shape and still looks to be about that way. The pool store said he always kept it in check and judging by the rest of the house I believe them. So I went along with the bring it in and have the store test it last fall and come about October they said that it was now cold enough (I live in Atlanta) to basically not worry about the pool until it got warm again. So I did just that (aside from keeping it from freezing). The pool wasn't closed or drained or tested in the winter. So early April I start bringing samples in. I remember the first time I went in they had me dump either 10 or 25lbs of Calcium, so Alkalinity and so on. So I know Calcium was low, just not sure what it was because they never tell me levels, it's just buy this and you'll be great. Anyways, I kept going there every week or so until my Algae issue. I had a very small amount of mustard Algae on the walls one day and went to the store where they gave me a quart of Copper Algacide and told me to dump it all in. I went along and it did the trick with the Algae but then slightly stained the gunite blue/brownish. Since then the pitting in the concrete has showed up more as it's now highlighted (so I've started paying more attention to it). Needless to say I wasn't happy that my pure white pool was now stained so I started reading this forum and am now doing everything on my own. I've bought the Taylor 2006 kit and have kept everything in perfect check. My pH has never been lower than 7.2 or higher than 7.8 since I've been testing. My trips to the store before self testing always yielded a "looks pretty good just add a little acid or a little alkalinity up". My numbers right now are this

ph 7.2
FC 3.5
CC 0
TA 140
CH 290
CYA 80

Now when I started testing about a month ago my CYA was near 100 but I stopped with the Trichlor pucks and have been using bleach. Also, my CH was steady at 200 which the pool store said was fine but since I noticed a little pitting I decided to up it to 290 a few days ago (was shooting for 300 but close enough). Anyways, just recently (last month or so) I've noticed small black marks on the bottom of the pool, there are maybe 2-3 visible from outside the pool and maybe 2 more so small you need to swim to the bottom to see them. None of them are bigger than a dime, probably half dime sized to bb sized. When looking close it looks like the plaster is worn through to another layer i believe.

So here is my long winded question. Does this mean I am going to have to resurface my gunite? This the answer I get when I search for this issue everywhere. Is it not okay just to do some sort of patch repair? I feel it's so minor how in the world could it come to this, needing a 3-4k resurface job? The pool seemed perfect and still looks almost perfect. I don't know if these marks were there last September but I have a feeling they weren't. Sorry for this long winded post I just wanted to get the whole story out. It just doesn't make sense that the plaster could be eaten all the way through already. Is it possible this all happened in the winter? I really wish I had discovered this forum back in September

Anyways, if anyone read through this mess and wants to offer hopefully what is soothing advice I'd appreciate it.

 

[LeeM2]

I have some very small black dots in my pool. They are probably 2-3mm in diameter, but I've had a lot of them in one spot, probably the size of 2 quarters. Not sure what they are, but if I rub them with a piece of chlorine tab, covering them up in chlorine they seem to go away after some time (not sure how long, but next morning they were gone). I also got the green dots, not sure what they are and hot to get rid of them.

 

[Bama Rambler]

You can do as Lee and hold a trichlor puck on them and see if they change. Report back if they do. If they don't go away with that you can hold a vitimin C tablet on them and see if that helps. Report back either way.

One thing I noticed is that your FC isn't high enough unless I missed the SWCG. Which I don't think I did because you said you used bleach. Your FC for a CYA of 80 should never be lower than 6ppm.

 

[poolquestions4u]

Hmm that seems to me like it's just an organic stain if you can get it to go away with Chlorine (from what I've read online). Do the green dots look like the plaster has worn through? My spots are clearly something showing through below the plaster. What's confusing is that the plaster doesn't seem to be eroded that much, it's definitely pitted more in the ares where the dark spots are but it almost seems like it's just a very thin area of plaster. My main question is still, does the pool need resurfacing for such minor spots and will it get bad that quick? I'd love to be able to just drain and repair those spots. If I could get another 3-5 years with just a few tiny patch jobs I'd be happy. Does this sound realistic to anyone? I hate reading websites that say "dark areas where gunite is showing = need to resurface" There's gotta be a threshold.

 

[poolquestions4u]

You can do as Lee and hold a trichlor puck on them and see if they change. Report back if they do. If they don't go away with that you can hold a vitimin C tablet on them and see if that helps. Report back either way.

One thing I noticed is that your FC isn't high enough unless I missed the SWCG. Which I don't think I did because you said you used bleach. Your FC for a CYA of 80 should never be lower than 6ppm.

I may try the trichlor puck, how thick does the plaster layer usually run?

As far as my FC goes this is odd. I've read many things that support what you're saying but I've honestly never had a FC of more than 6-7 (when I pour a whole jug of bleach). I've never had any problems except one minor bout with mustard algae, but I'm pretty sure I didn't have any chlorine in for about a week. I do have the Nature2 and run the pool about 10-12 hrs a day. 1-3PPM is where I usually keep the chlorine. Now there are still some copper stains (about to remove them with some ascorbic acid) and I have to keep my water on a metal sequestering program so this may be what's helping out with the algae.

 

[frustratedpoolmom]

One thing I noticed is that your FC isn't high enough unless I missed the SWCG. Which I don't think I did because you said you used bleach. Your FC for a CYA of 80 should never be lower than 6ppm.

For emphasis - your FC is too low. If you don't plan to replace some of the water to lower the CYA Level, then you need to keep your FC according to the CYA chart.

If what you are seeing are the beginning of Black Algae, you need to scrub those spots with a SS brush so the chlorine can attack the insides. Try that, see if they smear or fade.

AA won't help copper staining. You'll likely have to live with it until the pool gets refinished or acid washed if either is in your future.

 

[poolquestions4u]

I really hope it is black algae. Does it make sense for it to look recessed in the plaster?

As for the AA not helping copper staining... Are you sure this is correct? Before I empowered myself with the internet I used a bottle of pool stain treat that the pool store sold me. I believe it was oxalic acid. This did the trick of lifting all the stains, both blue and brown. The only problem was that my copper levels were about 1ppm in the water so it quickly plated back out after a few hours. I was led to believe that oxalic and ascorbic acid worked in the same way on metal stains and both were affective. Is there a difference? BTW, I really appreciate the help people. I'm not trying to be argumentative at all, I just want to clarify as I'm getting conflicting information. I guess I'll find out this weekend when I give it a try.

 

[LeeM2]

Hmm that seems to me like it's just an organic stain if you can get it to go away with Chlorine (from what I've read online). Do the green dots look like the plaster has worn through? My spots are clearly something showing through below the plaster. What's confusing is that the plaster doesn't seem to be eroded that much, it's definitely pitted more in the ares where the dark spots are but it almost seems like it's just a very thin area of plaster. My main question is still, does the pool need resurfacing for such minor spots and will it get bad that quick? I'd love to be able to just drain and repair those spots. If I could get another 3-5 years with just a few tiny patch jobs I'd be happy. Does this sound realistic to anyone? I hate reading websites that say "dark areas where gunite is showing = need to resurface" There's gotta be a threshold.

what-are-these-geen-brown-black-dots-t24357.html

I have pictures in very first post. I don't know what the green ones are, but chlorine tab doesn't seem to work on those. It does seem to get worse and I'm not sure what the deal is. I stopped shocking pool and haven't shocked it for almost two weeks now, but my chlorine level stays around 5 with 30 cya. I do use tabs though and go through probably 4-5 a week. I'm getting bleach\chlorine this week and may switch to that.

 

[frustratedpoolmom]

I really hope it is black algae. Does it make sense for it to look recessed in the plaster?

As for the AA not helping copper staining... Are you sure this is correct? Before I empowered myself with the internet I used a bottle of pool stain treat that the pool store sold me. I believe it was oxalic acid. This did the trick of lifting all the stains, both blue and brown. The only problem was that my copper levels were about 1ppm in the water so it quickly plated back out after a few hours. I was led to believe that oxalic and ascorbic acid worked in the same way on metal stains and both were affective. Is there a difference? BTW, I really appreciate the help people. I'm not trying to be argumentative at all, I just want to clarify as I'm getting conflicting information. I guess I'll find out this weekend when I give it a try.

Sure, BA can hide in the little nooks, etc.

As for the AA and copper, No, I'm not sure, but it's what many of our stain experts have told me. I've read here that there have some cases where AA treatments have actually made copper staining worse. Some people have had success removing their alleged copper stains and others have not, having to resort to an acid wash. YMMV.

Be sure to post back with an update on how it goes.

 

[poolquestions4u]

I'll let yall know how it goes. I'm going to try and get to the bottom of this black mark problem before I worry about the stains. When I do tackle the stains, my plan is to go slow with the AA and use the minimum amount necessary to lift the stains. One thing I was thinking (again I'm very new to pools so this might sound crazy)...

Since there is no good way to get metals out of the water without draining, do you think it would be possible to try and get them to plate out onto the cartridges? I don't know how quickly the plating happens but imagine this: Wait til chlorine is gone, lower ph, pour in the AA and let the pumps run. After the stains dissappear, SLOWLY add bleach to the skimmer as the pumps are running. My thought is that the chlorine will react with the metals and plate out onto the cartridges. Then, take the cartridges out, soak them in water and add some AA to remove the stains, take them out of the water and rinse off! Repeat as necessary. I'm guessing the problem with this is that the chlorine level would rise in the pool as well and possibly plate out. It all depends how quickly the stains lay down and if they'd hit the cartridge material harder than the plaster. Anyone tried this?

Just a thought, I may just go with the sequestering method though.

 

[frustratedpoolmom]

Its' far more likely the stains will simply redeposit on the pool surface.

 

[poolquestions4u]

Well I tried the chlorine puck method. Scrubbed the mark with a Trichlor and even crushed one up and let it sit over night. It seems to have made it worse, I probably removed some more of the plaster. So it certainly appears to be the gunite showing through. A closer look revealed it to be more gray colored than black. So what are my options from here? I need to make this surface last as long as possible as a resurface isn't in my near future. I may just call a contractor and get estimates of a patch job. I know I could do it myself but I get a little nervous at the idea of draining the pool with these horror stories I read.

 

[Guest]

Look for a diver. Lots of guys can dive a pool, cut out the loose/bad plaster area and make an underwater repair. It will show up as a patch, but should be fine for quite a while. Plaster is typically about 1/2" thick over the gunite.

 

[geekgranny]

Well I tried the chlorine puck method. Scrubbed the mark with a Trichlor and even crushed one up and let it sit over night. It seems to have made it worse, I probably removed some more of the plaster. So it certainly appears to be the gunite showing through. A closer look revealed it to be more gray colored than black. So what are my options from here? I need to make this surface last as long as possible as a resurface isn't in my near future. I may just call a contractor and get estimates of a patch job. I know I could do it myself but I get a little nervous at the idea of draining the pool with these horror stories I read.

My very good friend has a white plaster pool that is 22 years old. The plaster has been delaminating over the past few years so she had had someone patch the spots as she cannot afford a new plaster job. The patches, some as big as 6" in diameter have held for a few years and blend in well with her light plaster. Your spots are small so I would catch them ASAP.

I just recently discovered a patch job I did under a return, many years ago. I had forgotten all about it. My plaster is blue and the patch is white but I cannot see it unless I look really closely.

What concerns me is that the plaster is lifting after only 7 years. This indicates either some kind of abuse in the areas of divots or the plaster might not have bonded to the gunite as well as it should have. Keep a close eye on all the plaster.

The stuff I used for my patch job was 2 part epoxy putty and possibly done under water. It's been so long ago I can't remember. The patching on my friends pool was done with pool full of water. It just occurred to me that a way to do larger spots might be to use a rolling pin (prior to applying the patch) to get it large enough and thin enough. But you only have tiny spots to do. Rolling pin might be of help here too. One thing to keep in mind is that the patch materials set up really fast. If I was doing it myself I would rent some scuba gear to do it. (I'm certified so no problem renting equipment.) If you have someone do the patch for you, I would highly recommend that they do it using scuba gear to get the patch done properly. It is extremely hard to do a good job without staying right there to work in the edges before it sets up.

Copper....I used Ionization for 18 years. I had my pool re plastered in 96. I was very lucky as the plaster has held up beautifully with many years left IF I can live with the copper staining. I'm just going to live with it and hope that I can lighten it somewhat over time. My 96 finish has had three acid washes mainly to remove thick layers of heavily stained calcium scale after the pool became a swamp over three winters. The last one was in 2008. The pool had a major leak all 2007 but I kept water in it by spending, I'm too embarrassed to say, way too much money keeping it filled. Two pool services could not find the leak. I couldn't find it. But then a retired pool guy said, "It sounds like it is in your light niche." It was AND I had done the dye test several times but it did not suck in the dye until I removed the light bucket. Anyway in late fall 2007 I let the water go down and basically closed the pool without a cover. The water stopped draining right at the bottom of the deep end light leaving about 18" in the shallow end. It stayed this way throughout the winter and into summer to let the thousands of tadpoles mature. (We had an explosion of Copperheads that year and 2009 because of all the good food, hundreds of additional frogs.) Over the winter, when the pool sat, the Floatron Ionizer was throwing gobs of copper into the water.

Summer 2008 I drained the pool and acid washed removing most of the calcium scaling and the attached stains. I didn't hit the bottom of pool too hard because it is so hard to control the acid on a sloping horizontal surface without getting too much etching in some areas. But I did get the scale off of all vertical surfaces. In some places I even used straight 3x.xx MA. With older plaster one has to be very careful doing acid wash. With blue plaster you can tell you've overdone it when the runoff from poured acid is dark blue.

After the acid wash we were terribly anxious to get the pool filled so we could use it. After it was filled I then saw the copper staining that the acid wash didn't remove. It starts at a distinct line where the water level sat when it was a frog pond all those months.

So, I continued to use the Floatron, adding more and more copper to the water. I had not discovered TFP, and didn't have a good grasp on other values for the water other than pH and FC. Floatron stayed in pool until summer 2009 when I discovered TFP. By this time more calcium scale had developed. It hid the copper staining. I did an AA treatment in Fall 2009 which did release all of the iron staining. The iron holds more firmly to calcium scale than plaster. The iron does not come from our water, rather the immense amounts of sand/silt/mud/dust that goes into the pool constantly. After the AA treatment I kept the process going somewhat by using large doses of sequestrant all winter into spring, and keeping the pH around 7.2. Loads of calcium scale release during that time. All other values were kept on target too.

For two months I did not have my pump and filter hooked up so used two submersible pumps with Slime Bags, for filtration, 24/7 and an Aquabot, with fine filter bags running about 10 hours a day. When I got the new pump, VF, and big new filter, Quad 80 sq ft, put in it took about three weeks to filter out all the calcium particles.

Copper stains now seem to be darker than after the 2008 acid wash, maybe because of using the Floatron for one more year, with calcium scale somewhat covering it.

I'm continuing to keep the sequestrant in with pH hovering around 7.2 and calcium scale is continuing to release. That is very obvious.

I'm not really sure about the copper staining but it looks like it might be lightening just a bit. This is very subjective. If it is lightening it will be a very slow process and possibly still be around when it is time for a replaster. The 1996 plaster job was probably much better job than anyone could expect. The plaster is still very thick all over the pool. Amazing as, until 2009, when I discovered TPF, the plaster was very abused due to my ignorance AND three heavy acid washes.

BTW.... with the age of the plaster I might be looking at disaster doing any more acid washes.

I don't think many plain plaster jobs are or are going to as good as the one I LUCKILY got in 1996. Another indicator of the superior plaster/job is that the pool sat exposed to elements, with over half the plaster exposed for many, many months, including part of the sizzling Texas heat and sun in summer 2008. It was fully drained for over a month in the middle of Texas summer before my friend from the west coast got here to help me. Can we say, "What a great friend?" :!: :!: That kind of treatment to plaster is not a good thing to do but my pool didn't seem to suffer from it.

So to sum up or clarify some points. There is no guarantee that eve an acid wash will remove copper staining. I did the AA treatment, fall of 2009 for three weeks. It did help loosen the calcium scaling somewhat. I did the AA treatment that long because, when the water is cold chemical reactions slow down considerably. My "superior" plaster is holding up to my mini acid treatment, for almost 10 months now, but I suspect most plaster wouldn't handle it without some kind of damage. Acid washing is really hard on any plaster or composite plaster. You can only do it so many times, during the life of the plaster, before you start taking away enough plaster that the gunite starts showing through.

Any copper added to a pool is just too risky and really is never needed. It's an extra expense AND it will eventually cause staining, if enough cooper has built up to do any good. Many algaecides contain copper. There are very few good reasons to use algaecide as bleach kills virtually all algae. One use for algaecide is when lowering the FC to do an AA treatment. It basically just keeps the algae from growing but is not necessary in a properly balanced pool with good flow and adequate FC. One may never get rid of copper stains once they are deposited. I would suggest to anyone who insist on using copper to get a plaster that is the color of copper staining. Iron staining is easy to get rid of. I don't know about the other metals that stain though.

Cwculver, if I were in your situation, I would be very wary of doing a full acid wash as the released plaster in those spots may be an indication of more delamination coming. Acid wash would only exacerbate the problem.

gg=alice

 

[poolquestions4u]

Wow thanks for the help everyone, especially the detail geekgranny. Trust me, as a new homeowner and new pool owner, the more I hear about other people's experience, the better I feel. Regarding your comment about being concerned that the surface is only 7 years old...

Yes, I agree, I am concerned that I'm dealing with this already. But I really really do not think that the pool was abused. The guy I bought the house from was very meticulous and was involved in the pool building himself. He kept up with it, I know that much. I guess the only "abuse" you could say would be me ignoring the pool this past winter due to the horrible advice of my local pool shop (I now drive 10 min out of my way to another shop if I HAVE to buy something from a pool store).

Now the other question is, was the plaster job done wrong? You say that plaster should be about 1/2" thick? I couldn't find where I read that, just tried and skimmed through again. Well the area where the dark spots are showing is certainly thin, the difference between the "good looking" plaster all the way down to the gunite is only about 1/8" to maybe a 1/4" at best. That's why I thought it might just be black algae, but I've ruled that out. Maybe the plaster is just to thin in certain areas Also, you use terms like "lift up" or release from the gunite. To me, it seems that the plaster has been eroded through and not that its delaminated and chipped away. Is this a result of a poor bonding job or just plaster that was spread too thin?

As for the skuba idea. What about simply snorkeling with an extended hose? I may give that a try. What was the brand of the underwater curing plater you used? Do you remember? Thanks again for the help!