Plaster Etching, staining or BOTH?

[AmyCJeff]

Our pool was completed April 2020. We have a white plaster chlorine pool (but it is UV/ION so it uses a bit less chlorine than a "normal" chorine pool)
It is 18,000 gallons. I have TWO issues going on with my pool plaster...but after SCOURING these forum I think I have figured out the answer to one of the problems. I have Plaster etching. This explains the little white dots (small and large) all over my plaster.


BUT, I need help with the SECOND issue. I have "Staining". I am hoping someone here can help me identify the issue and possibly figure out how to get rid of them.

First of - Chemical Levels (we check these every 5 days in the winter and every 3 days Spring, Summer and Fall)
FC = 3 - We do a good job of maintaining this, but it does drop low sometimes
TC = 3/6 (6 is the total Bromine)
TA = 180 (this is high....but we can never figure out how to get it lower...since everything else is measuring within range)
Ph = 7.8
Hardness = 1000+ (We don't know how to get this level down...but it always registers high in winter and then over summer it is more in range)
Cya = 100


Here is what I know:
- We live in Vegas, so the water is "hard" and full of calcium
- It is not calcium build-up paired with dirt. The area was rough...but we sanded it. It is now smooth but the stains remain
- We recently treated our pool with the "Bosh Chemical Vanish Pool Sail remover" (citrus based) so I know the stains are not removed using a "citrus" based cleaner. This treatment did work great on removing some other stains we had (related to using the wrong sand paper...ekk!)


Any help would be GREATLY appreciated! It kills me to see our pool not look pristine and new! These are the best photos I could get. The stains show up much better when it is cloudy....

 

[reggiehammond]

Can you advise what you use to test the pool water? Your chemistry is a bit of a mess, but before commenting more, I want to make sure it’s from one of the recommended pool test kits.

Swimming Pool Test Kits Compared

What pool test kit should I buy? Why shouldn't I use test strips? Our recommended test kits will pay for themselves in no time!

www.troublefreepool.com

Also how are you chlorinating? UV and chlorine aren’t exactly friends. UV is not a recommended method as the sun gives you all the UV you could possibly need… for free. Your FC levels are below the minimum thresholds for a CYA level of 100. The CYA test also gets less reliable over 90, so your 100 might be 150, 200, or worse.

The only way to manage calcium hardness is to replace water. The same is true for CYA - you have to replace water to eliminate.

Calcium hardness at the levels you report, if correct, are a very likely source of the scaling issue you’re seeing in your pool. With that said, some of the spots look more like stabilizer staining, etc.

Besides the citrus cleaner - what else have you added to the pool? If you read around on TFP, you’ll read thousands of stories of people who arrived in similar results from following random advice, or worse, information from the pool store.

The TFP method is dead simple and we can get this straightened out, but it’ll require some work and diligent self-testing.

 

[AmyCJeff]

Thank you for your quick response. As I am reading more here, I think I have figured out that I am not using the correct testers...I have attached pic of what I am using (Pic #11 & #12)


We really have tried to limit what we put in our pool, here is what we use:


- Liquid Chlorine (we use this only on occasion)
- Chlorine tabs (in a holder that sinks to the bottom of the pool) - They last a lot longer
- Pool Shock (use this about every 3-4 weeks doing summer) - pic included (Pool shock). PB told us to do this
- Muratic Acid
- After using the citrus cleaner, we used a PH Downer - to get the chemical "back" in balance. Only used it once..about 1 month ago (Pic #13)

I am completely open to learning and using a different method (especially if it is the "best/corret" method)....


When you say "stabilizer staining"....what do you mean by that?

 

[ajw22]

Welcome to TFP.

Your entire method of pool care is different then TFP methods. I suggest you review the links below to learn what we are all about. Then if you want to change to TFP methods we can guide you.

What does not work is mixing methods and picking and choosing what you like and don’t like. You seem to realize your methods are not working. TFP methods are working for our hundreds of thousands of members.

TFP does not recommend the UV/ION low chlorine method of pool care for outdoor pools.

It is your pool and your choice.

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[AmyCJeff]

Thank you for the response. We were new to pool ownership when we had ours built 3 years ago. We simply followed "pool maintenance" procedures that our PB told us. We are definitely open to a better method. As far as UV/ION...again, it was something our PB recommended for us (based on size I think...because my brother had a smaller pool built by the same PB and he did not recommend it). I believe it is easy enough to convert to a "normal' chlorine pool...I think we just would need to turn off the Bulb that is used. All that to say....I want to do whatever it takes to keep my pool looking as pristine and new as long as possible....I am not looking to ruin such a huge financial investment I am reading through your link right now.

 

[PoolStored]

I am not looking to ruin such a huge financial investment

This is the best perspective you can have.

 

[ajw22]

First step is to get a good test kit. Either the Taylor K-2006C or TFT Test Kits

Once you have your test kit post your test results and we can discuss next steps.

Also download and get familiar with PoolMath

They are our key tools for pool care.

 

[AmyCJeff]

Purchasing now
So..two questions:
1) should I turn off my UV/Ozone system ASAP?
2) If and when I get to the point that I finally have my chemicals properly balanced and maintained...will that be the key to getting rid of the stains/preventing them?

I will be back in a few days, once my test kit arrives

 

[mknauss]

Great choice in getting a quality test kit.
Your first post said UV Ion. What exactly is the equipment?
If UV Ozone, you can leave them on. They do not do harm, other than consume some chlorine and raise the pH a bit.

The items you showed adding. The 'bags of shock' are calcium hypochlorite. That product should be banned from sale in our area. No reason whatsoever to add calcium to our already high calcium water. That, and the dry acid you used, could have caused your staining. How did you put those products into the pool?

 

[AmyCJeff]

Thank you for responding

I typed it wrong...we have the UV/Ozone system. I will leave it alone for now.

- The Pool Shock : Our PB advised us to use this during the summer. So, we have used it every 3-4 weeks From May-Sept, since May 2020. again, he explained it as a "chlorine" shock. I didn't even think about the Calcium it was pumping into the pool.... We add it around the edge of the pool (excluding swimstep areas) per the instructions.
- The Dry Acid...I Used it once. Added it to the deep part of the pool and let the filter run for 24 hrs. I only added this to bring down the PH after the citrus cleaner was added (per the advice of the company that made the Citrus cleaner).

- Unfortunately, I noticed the staining about 6-8 weeks ago....several week BEFORE using both the Citrus cleaner and Dry Acid....

I am going to guess that if I can get my Cyanuric acid and alkalinity to the proper levels, I won't burn through/need so much chlorine and I won't have the need to "shock" the pool with chlorine. Problem is, from everything I have read tonight...the only way to lower those levels is to drain the pool and fill it with new fresh water. Which brings me to another question...how often should you have to do that?

 

[reggiehammond]

Pool shock is typically used because chlorine pucks are incapable of maintaining a pool between weekly pool visits. The pucks dissolve, free chlorine (FC) falls, and algae can gain hold. Before it really shows up to the homeowner (it’s invisible early on), the industry accepted method is just hit it with a bunch of CalHypo (shock.) It knocks it back, new pucks added, rinse and repeat.

The method borderline works until CYA or Calcium get too high and there’s a whole host of excuses employed to get you to drain a bunch of water. “Chlorine lock” comes to mind as a prime scapegoat, even though it’s not a real thing.

Dry acid is less preferred to Muriatic acid, especially for pools with a salt water chlorine generator.

Most areas of the USA, if using TFP methods, would never need to drain their pool. Your area and the desert SW are a bit unique - high evaporation, little rainfall, and fill water content high in minerals (calcium.) Your goal is to never add calcium, as your fill water will do that for you. Do you have a water softener? One of the best things you can do is get it plumbed to allow for you to use that to refill pool from evaporation loss.

 

[reggiehammond]

Sorry - forgot to answer two other questions:
I asked about CYA addition as it’s acidic and causes staining if just broadcast into the pool and allowed to dissolve on plaster.

As for staining - you should expect zero staining from a properly maintained pool. As I just mentioned above - you will need to be very careful with calcium given the fill water and evaporation.

 

[mknauss]

We add it around the edge of the pool (excluding swimstep areas) per the instructions.

Is that in the area of the staining?

If you use raw tap water for fill due to evaporation, you will need to drain the pool about every 2 years, might get 3 years if lucky. With soft water, you can eliminate that nearly entirely.

 

[AmyCJeff]

Mknauss - thank you for your response. We do add the "shock" around most of the perimeter of the pool, which is were some of the staining is. Weird thing though....about 60-70% of the perimeter of the pool does NOT have staining...only certain areas. Also, I guess I can see where the "Shock" granules can "stain" the pool by creating the white patches/circles. But, I don't understand how the Shock granules can cause the dark/dirt looking stains.

We tap into our irrigation system (not tap water...but it is probably the same water?) for our auto-fill system. We are going on 3 years...so I am thinking that draining and refilling might be our best bet at this point. Especially due to our Cyanuric acid and Calcium levels. Although we are getting into our HOT season...so we probably are going to have wait until after summer


ReggieHammond - Thank you for response as well I get what you are saying about vicious cycle of pucks and shock. I also think we are stuck in a cycle of Constantly using Chlorine because our Cyanuric Acid and Calcium being soo high. From the point forward, I am not going to do more shock treatments as that is exacerbating my Cyanuric Acid/Calcium issue. I will stick to pucks and liquid chlorine for now.

When you say CYA addition can stain - is that the same thing as the Dry Acid/Ph Downer I used once? As noted above...I get how shock/chlorine...etc can "stain"the pool....but I would think it would stain it "white" and cause the white circle stains..but I don't understand how it can cause the dark/dirt looking stains. Plus, I noticed the staining BEFORE I used Dry Acid.


Final question...is there any hope (once I know what my chemical levels currently are and what needs to do to get in to the proper levels) of getting rid of the staining....or is more than likely permanent?


Thank you again for all of your help and patience as I learning all of this stuff.....

 

[mknauss]

Although we are getting into our HOT season...so we probably are going to have wait until after summer

Draining - Further Reading

www.troublefreepool.com

But, I don't understand how the Shock granules can cause the dark/dirt looking stains.

You could easily have algae. You likely have very low FC based on what your CYA is. We do not know the actual numbers, but your methods of maintenance imply that those will be true.

 

[Poolbreh]

@onBalance has contributed some great articles on spotting.

White Spotting of New Plaster Pools

The problem of plaster spotting has been an ongoing puzzle and controversy in the swimming pool industry for over three decades. The generally round, smooth-yet-unsightly white soft spots in new plaster pools have long been a source of contention among pool plasterers, and pool chemical service...

www.troublefreepool.com

 

[AmyCJeff]

Ok....my test kit arrived last night and used it this morning.
My test results are a MESS!! Here they are:

FC = 5 (did the FAS-DPD test as I did not have the testers needed to do the DPD test method)
Combined Chlorine = 0 (did the FAS-DPD test as I did not have the testers needed to do the DPD test method)
Calcium Hardness = 1575 (did the recommended test if high calcium as anticipated)**
TA = 300 (did the recommend test if hight TA was anticipated)
Ph = 8.0
CYA = 110

I don't even know where to begin on this....except drain the pool and start over....any help is GREATLY appreciated

**EDITED to Add :
1) Pool water is very clear/blue color. Not cloudy/greenish
2) I should note that my Calcium might be measuring EXTRA High at the moment. That is because I added 2 lbs of Shock (18,000-gal pool) on 5/31....just a few hours before I came across TPS and found out that can increase my calcium levels. EKK! I am speculating...but I m guessing this will drop a bit as the "shock"dissipates??

2) Which of the chemical imbalances should be addressed first?
- It appears that the only way to lower CH and CYA is drain some percentage of the current pool water replace it with new. I need to calculate how much I need to drain. Method : No Drain/Refill method. Maybe give some time for the Calcium to drop (since I added the shock). So maybe leave this one alone for the time being and move on to addressing TA?
- It appears that I can lower the TA by lowering my PH to 7.0 (using muriatic acid) then aerating the pool water. I have a "booster jet" setting in my spa (looks like the spa is an extreme boiling pot of water) and a spill over water feature (18 in wide by 2 ft high). I would turn both of those on until Ph rises back to 7.8. Continue cycle until TA is in acceptable range.
- FC is addressed by adding liquid chlorine. Add this once I get my TA to acceptable levels?

 

[clambert1273]

Test your fill water then use
PoolMath to figure out how much water to exchange.

See here:

Draining - Further Reading

www.troublefreepool.com

 

[V___25]

I will stick to pucks and liquid chlorine for now.

The pucks will cause your CYA to rise. The pool math app can you tell by exactly how much in the Effects of Adding section. Just be careful of pucks so you don't get CYA too high over time.

 

[reggiehammond]

Ok....my test kit arrived last night and used it this morning.
My test results are a MESS!! Here they are:

FC = 5 (did the FAS-DPD test as I did not have the testers needed to do the DPD test method)
Combined Chlorine = 0 (did the FAS-DPD test as I did not have the testers needed to do the DPD test method)
Calcium Hardness = 1575 (did the recommended test if high calcium as anticipated)**
TA = 300 (did the recommend test if hight TA was anticipated)
Ph = 8.0
CYA = 110

I don't even know where to begin on this....except drain the pool and start over....any help is GREATLY appreciated

**EDITED to Add :
1) I should note that my Calcium might be measuring EXTRA High at the moment. That is because I added 2 lbs of Shock (18,000-gal pool) on 5/31....just a few hours before I came across TPS and found out that can increase my calcium levels. EKK! I am speculating...but I m guessing this will drop a bit as the "shock"dissipates??

2) Which of the chemical imbalances should be addressed first?
- It appears that the only way to lower CH and CYA is drain some percentage of the current pool water replace it with new. I need to calculate how much I need to drain. Method : No Drain/Refill method.
- It appears that I can lower the TA by lowering my PH to 7.0 (using muriatic acid) then aerating the pool water. I have a "booster jet" setting in my spa (looks like the spa is an extreme boiling pot of water) and a spill over water feature (18 in wide by 2 ft high). I would turn both of those on until Ph rises back to 7.8. Continue cycle until TA is in acceptable range.
- FC is addressed by adding liquid chlorine

I would test CH again, just to confirm the 1575 is correct. That's one of the highest I recall seeing, but if correct, would help explain the staining and scale.

You'll need to address the CH and CYA, at the same time, with a water exchange. By effectively dumping most of the problem water, you'll set your self up for better success, and easier management. Once you confirm CH, report back, but CH will dictate how much replacement you need. The good news is that replacement of water is super easy, nor that expensive.

TA is not a huge issue and will likely reduce with water exchange - TA simply encourages pH to rise. You then add acid, pH rises again, and you repeat process. There's no need to be aggressive, just let it change, add acid, rinse and repeat. You'll eventually find the point where the TA is happy and pH stops changing.

Once you've replaced water to get CYA and CH to normal ranges, you might consider a small SLAM, but with mostly fresh water it'll be easy.