Pool Gal Troubles

[paganok21]

Hey ya’ll. Newbie here who has done a massive amount of research on the forums trying to get it all right. I’ve run into a few pool builder challenges that threw my chems out of whack just when I almost had them perfect!

First off, I live in hot, dry Arizona and have a 10,000 gallon salt water inground pebble pool with a small raised spa with waterfall.

The only problem I’ve experienced with my water is a white scale build up on the tiles/grout. I brush every few days to keep that at bay but wowza it comes back in just one day. I can’t imagine that is normal. My PH is always high (new pool perhaps or the waterfall) so I’m adding about 1/4 gallon muriatic acid twice a week to keep it at bay. Salt water pool so no other chemicals really. Oddly enough, my FC is always high even with the SWG running at 30%. During initial start up I was told: keep it at 50%. FYI- I run filter on high for 4 hrs per day and low for 5 hrs per day. I was also told I would never need to shock my salt pool - so I haven’t. Pool was set up in late February.

With all that background info- here’s where I’m looking for help. We had a leak and the salt generator was out for a bit so we had to use chlorine tabs and things got thrown out of whack. We are back up and running and I decided to take a pool sample into Leslie’s for help. Perhaps this was my biggest mistake! Before that, my water was clear but I knew my chlorine was running high and I continue to get lots of the scaling on my tiles. I check my own Chems twice per week- FC, PH, TA. I’ve never checked the CYA or Calcium or Phosphorus on my own. I also purchased a salinity digital tester which puts my salt at 3800ppm (builder put a little too much in!).

Below are my current levels. With these, Leslie’s recommends I regularly shock the pool, bring down my FC with their product, increase my CYA with their conditioner and bring down my Phosphates using their NoPhos.

I’ve read our fabulous TFP forums and I know your feelings on the NoPhos - so - I do not plan to add that unless you disagree per my levels below. I also have turned my salt cell down a bit and hope to see my chlorine drop on its own. I’d rather not do that with chemicals (unless I have to?).

My questions:
1. Should I be adding shock every few weeks with a salt pool? Wouldn’t that just make my levels higher?
2. Do you agree that I should use conditioner to increase the CYA?
3. My salt generator is at 30%. With the Chlorine levels you see below, should I lower that? I also find it off that my CYA is low but my Chlorine is so high. I thought CYA is needed to keep chlorine in the pool. With CYA low, I’d assume chlorine would be low too.
4. Do you have any additional advice on how I can control the scale deposits based on my water chemistry below?

Free Chlorine: 6.3
Total Chlorine: 7.02
PH: 7.3
Total Alkalinity: 90
Calcium: 310
Cyanuric Acid: 40
Phosphates: 421

I’m so appreciative for any advice. Thank you so much!
Kim

 

[HermanTX]

Welcome to TFP.
The very first thing you need to do is stop going to Leslie's and then order a proper test kit. Test Kits Compared
if you are going to take care of your pool then you need to do your own testing.

In this forum we live by 2 main cornerstones - do your own testing and follow the FC/CYA Levels

No - you do not need to shock your pool weekly. If you maintain your FC per the FC/CYA chart for a saltwater pool then you will be fine
Your CYA should be in 60-70 range when using a SWCG but only way to know is to do the test yourself - don't rely on pool store results

Suggest you also download the PoolMath app as that will help you set your SWCG to balance runtime vs SWCG output. This app lets you select your specific SWCG so it provides answers based on the mfg. output data for your SWCG

Hope this helps.

 

[Rancho Cost-a-Lotta]

Welcome to TFP!

To answer most of your questions, we need a full set of reliable test results from a TFP recommended test kit. We don't trust pool store testing and don't provide guidance based on them. The kits from TFtestkits.net provide the best value for the residential pool owner.

TFP doesn't recommend weekly shock treatments. If you maintain the FC level according to the FC/CYA Levels, there's simply no need for "shocking" a pool. Solid forms of chlorine add either CYA or calcium to the pool which can rise to a level where exchanging water is required.

Is your pool fill line connected to a softened water source?

With proper test results, we can take a look at your numbers and fine tune chemistry in a way that will reduce scaling tendencies.

Spend some time in Pool School. Here is a good set of articles to get you started.

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

Best wishes!

...I was typing this as @HermanTX posted, so understand if some of the info is redundant.

 

[paganok21]

Thanks so much. I’ve read through alot of the articles here but will pour through more forums per your recommendation.
Yes, I test using my own kit a few times per week. I use the Taylor 9-Way kit. The following results is where I’m at with that. My salt cell is at 30% currently and the filter runs 4 hours high (85%) and 5 hours low (45%). Salt is slightly high at around 3700/3800ppm. I have an auto leveler for the pool but it uses the city water. I do not have a softener or RO system.

Free Chlorine- 5 (top of the test tube)
PH: 7.8
TA: 90
CYA: <30 (I couldn’t fill the tube enough to get the dot to disappear on the test)
Calcium: around 400

And yes, I have downloaded pool math and it’s been super helpful in getting my PH and TA levels in check. The CYA throws me a bit though because I fill the little tube to the top but can still see the dot so the levels are less than 40. But my FC numbers are high (as you can see in my reply above). Pool Math doesn’t give me advice on being FC down but does advise to add conditioner. I’d love any further advice with my overall numbers and reducing the scale of anything jumps out at you. Thanks again!!

 

[paganok21]

I’m so grateful for your replies and help. Thank you

 

[HermanTX]

Thanks so much. I’ve read through alot of the articles here but will pour through more forums per your recommendation.
Yes, I test using my own kit a few times per week. I use the Taylor 9-Way kit. The following results is where I’m at with that. My salt cell is at 30% currently and the filter runs 4 hours high (85%) and 5 hours low (45%). Salt is slightly high at around 3700/3800ppm. I have an auto leveler for the pool but it uses the city water. I do not have a softener or RO system.

Free Chlorine- 5 (top of the test tube)
PH: 7.8
TA: 90
CYA: <30 (I couldn’t fill the tube enough to get the dot to disappear on the test)
Calcium: around 400

And yes, I have downloaded pool math and it’s been super helpful in getting my PH and TA levels in check. The CYA throws me a bit though because I fill the little tube to the top but can still see the dot so the levels are less than 40. But my FC numbers are high (as you can see in my reply above). Pool Math doesn’t give me advice on being FC down but does advise to add conditioner. I’d love any further advice with my overall numbers and reducing the scale of anything jumps out at you. Thanks again!!

The 9-way Test kit appears to be a K-1005. That will not do for chlorine testing. You got all the essentials except for FC so I would add this FAS/DPD Chlorine Test Kit

For CYA testing I do it in increments. I pour the mixed solution to a known level - like 80 and peer at the dot, if I see it, I pour in solution to 70 and peer in, I continue this until I do not see the dot and then use the reading where I last saw the dot. This way you are not staring down the tube as you pour. If you stare at the dot too long you will see it everywhere, so by going to each level then peering avoids that constant staring. Also, since I only go to the decade lines, I am never tempted to try to interpretate between them. Always use decade numbers for CYA

There is never any need to lower FC with chemicals, it will come down over time, especially in summer when more UV is present.

You can add stabilizer to increase CYA. You need to do it incrementally as you do not want to overshoot and it takes a day or 2 to dissolve so you have to be patient in testing after adding.

You can lower TA by adding MA but never go below 7.0 on the pH scale. Then let pH rise and repeat. TA will gradually move lower.

 

[paganok21]

You are the best, thank you! Yes, the K-1005 kit is what I have. I’ll definitely add the chlorine test you recommended to my arsenal.

Regarding cyanuric acid, I think my struggle with the test tube was that my level is too low. I did it slowly and tjhe lowest reading it will give me was 20 and I could still see the dot. I thought I was doing it wrong but the pool store confirmed the low level. At least they were good for something! I’ll take your advice with the staring method when I retest in a few days after adding the conditioner. I saw that black dot even in my sleep that night!

Regarding the scale I see on my tiles everyday- I assumed this is my CA levels. We are known for our hard water in this area. But, it’s still under 500. My PH is always high. Seriously I could test every 3 days and need to add acid every 3 to bring it down. Could that be my scale build up? Perhaps my PH is rising faster than the 2x per week I’m checking and I need to be adding acid more often? I’ll definitely test this theory but my question would be is this normal?

 

[Rancho Cost-a-Lotta]

Regarding the scale I see on my tiles everyday- I assumed this is my CA levels. We are known for our hard water in this area. But, it’s still under 500. My PH is always high. Seriously I could test every 3 days and need to add acid every 3 to bring it down. Could that be my scale build up? Perhaps my PH is rising faster than the 2x per week I’m checking and I need to be adding acid more often? I’ll definitely test this theory but my question would be is this normal?

Your CH level is currently in perfect range. It will continue to rise. How fast depends on the CH level of your top-off water. CH doesn't evaporate, it stays in the pool. Adding fill water adds calcium causing the levels to rise. When levels get too high, a water exchange is required.

Test the fill water CH...

Acid additions every two to three days is not uncommon. Depends on the TA and pH of fill water and the amount of aeration your pool receives, along with other factors. Newer plaster pools tend to require more MA additions.

In Pool Math, enable CSI tracking. In very general terms, higher CSI water (positive range) wants to leave calcium behind on the pool surface (scaling). Lower CSI water want to pull CH from the surface (etching). To avoid scaling tendencies, CSI should be maintained between 0.0 and -0.30. I estimated some values (temp and salt level), but your water is somewhere around ~+0.22. Lowering TA and maintaining a lower pH are the easiest ways to lower overall CSI. Read the article on CSI for more info:

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.troublefreepool.com

 

[paganok21]

Your CH level is currently in perfect range. It will continue to rise. How fast depends on the CH level of your top-off water. CH doesn't evaporate, it stays in the pool. Adding fill water adds calcium causing the levels to rise. When levels get too high, a water exchange is required.

Test the fill water CH...

Acid additions every two to three days is not uncommon. Depends on the TA and pH of fill water and the amount of aeration your pool receives, along with other factors. Newer plaster pools tend to require more MA additions.

In Pool Math, enable CSI tracking. In very general terms, higher CSI water (positive range) wants to leave calcium behind on the pool surface (scaling). Lower CSI water want to pull CH from the surface (etching). To avoid scaling tendencies, CSI should be maintained between 0.0 and -0.30. I estimated some values (temp and salt level), but your water is somewhere around ~+0.22. Lowering TA and maintaining a lower pH are the easiest ways to lower overall CSI. Read the article on CSI for more info:

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.troublefreepool.com

I love this! I didn’t know about CSI tracking. I’ve enabled and currently it says .3 as my ph has risen a little. Thanks so much!

 

[Bperry]

Also, just for reference your chlorine was not too high. There are old recommendations that say it should never exceed 4ppm, but they don’t take into account the CYA level. If you follow the FC/CYA chart, it’ll be fine.

 

[Rancho Cost-a-Lotta]

CYA: <30 (I couldn’t fill the tube enough to get the dot to disappear on the test)

Regarding cyanuric acid, I think my struggle with the test tube was that my level is too low.

For a SWG pool, TFP recommends a higher CYA levels than non-SWG pools, especially in the southwest. It's has to do with the way a SWG produces small amounts of chlorine throughout the day as opposed to one large dose. Take a look at the recommended levels for a plaster/SWG pool.





For CYA, you can target 60 ppm and work up from there if you wish. Higher CYA requires a higher FC as well (FC/CYA Levels). But daily loss should decrease as the FC is better protected from UV. Wait until you get your FAS/DPD FC/CC drop test since your kit can only measure up to 5 ppm (and not very accurately).

A bit more info on waterline scale. Some of this in unavoidable. Water wicks up on the tile and evaporates leaving calcium behind. This cycle can lead to a distinct ring at/above the waterline. You can scrub your tiles frequently to break up the build up, but once it's there it's very difficult to remove. I had my pool bead-blasted a few years ago. Cost was about $4 per linear foot. More info here:

Waterline Scale Removal - Further Reading

www.troublefreepool.com