New pool build / new pool owner issues with calcium build up in very short amount of time

[Agrabah]

Hello,

We filled up the beginning of December and recently I noticed significant calcium build up on the waterline at the tile pretty much everywhere.

Using a Tylor 2006C kit:

1/7

FC 2.4
CC 0.4
pH 7.4
TA 90
CH 270
CYA 30

1/11

FC 2.4
CC 0.6
pH 7.8-8.0
TA 90
CH 270
CYA <30 (not readable)

1/14

I took a sample to Leslie’s

FC 2.2
Total Chlorine 2.34
pH 7.7
TA 101
CH 185 (where did it all go?)
CYA 12 (where did it all go?)
Salt 3200

Is this normal? It was easiest to capture from the spa side but if I turn my auto fill off and let the pool water drop over a few days it’s very noticeable over there too. Initially I thought it was salt as they just added it about a week before I noticed it. Is this normal for less than 2 months?

 

[PoolStored]

I took a sample to Leslie’s

FC 2.2
Total Chlorine 2.34
pH 7.7
TA 101
CH 185 (where did it all go?)
CYA 12 (where did it all go?)
Salt 3200

"Stay away from the pool store testing, your test kit is accurate" - PoolStored.

What are the properties of the white stuff. Does it dissolve and go away if you splash water on it and wipe with your hand/towel? (if so, it is likely just salt that shows up on your blue tile). Is it hard to remove? Then likely scale.

Others will pipe up, but here is some reading to help.

Waterline Scale Removal - Further Reading

www.troublefreepool.com

 

[Agrabah]

I can rub it underwater and get it off but it’s kind of hard to do. When light hits it right you can see it underwater. Initially thought it was salt because of the timetable. Can’t really be sure anymore.

 

[PoolStored]

I can rub it underwater and get it off but it’s kind of hard to do. When light hits it right you can see it underwater. Initially thought it was salt because of the timetable. Can’t really be sure anymore.

Re-read the article I posted on removing scale. Maybe try the 3M pads.

Are you using pool math (PoolMath) and tracking CSI? Your CSI, assuming water temp of 80 Degrees and 20 CYA is .040. Fairly neutral. Download pool math and enable CSI tracking, and try to keep -.3-0.

Based on our experience, if you drive your CSI negative for a period of time, will be easier to remove (see article below and previous article I linked). Reducing pH will have the biggest impact (like 7.2), raising your CYA to 50, and reducing TA to 60, would put you at -.81. I wouldn't do that, I would reduce your pH to 7.2. As it rises, I would reduce it again. As you reduce your pH with Muriatic Acid in cycles, your TA will come down. If you get it down to about 60, pH to about 7.8, and get your CYA up to 50, your CSI would be -.24. This would reduce scale and allow you to remove the existing scale.

You don't indicate if you have a SWG or not. I assume you have a SWG because you measured salt. Either way, maybe fill out your signature and would help us?

Create Your Signature - Further Reading

www.troublefreepool.com

If you have an SWG (assuming you do), I'd get your CYA up to 70. This will help your CSI by about -1. You might do it in increments of 40ppm first, then 10 until you get there.

Do you have a K-1766 salt test kit? If not, way more accurate than the pool store. I'd get one.

Here is another article on scaling...

Calcium Scaling

Calcium scale on your pool is something we all want to avoid. With some elbow grease and a pumice stone for pools we can help you remove this eyesore.

www.troublefreepool.com

Summary:
1) Reduce your pH to 7.2 with Muriatic Acid. Use PoolMath to figure out how to do that with "effects of adding" function. You can do in increments to not overshoot. This will reduce TA.
2) pH will rise again. When it gets to 7.8-8, test your TA. If TA is above 60-70, reduce pH to 7.2 again.
3) Repeat until TA is 60-70, then let pH "settle" at 7.8-8.0. Don't drive it down again.
4) In parallel, add CYA (Chlorine stabilizer) by putting it in a sock and suspend in front of a return allowing it to dissolve. If you are truly below 30, add 40ppm (use pool math), then in increments of 10ppm until you get to 70 (assuming you have SWG. WAIT 24-48 hours after CYA is dissolved and pump running to retest. CYA takes a bit to circulate.
5) Monitor CSI in pool math...keep it -.3-0. pH will have the biggest impact.

Ask as many question as necessary, we are here to help!

 

[Agrabah]

Updated signature and the About Me, need to get models added later but it should be a better idea of what is going on for me.

I will run calculations later using Pool Math to see. The pool should be under PB's care for the first two months (which is almost up) and I want to take over when it is in "perfect" balance. This doesn't seem normal to me but I wanted outside opinions. I met with the company the PB is using for "chemicals" today. The reason I put that into quotes was because in the 6-7 weeks the pool has been filled they have not once added any MA. We even had several days of rain which is rare here, they still tested 7.6. They have only been swapping out the chlorine tabs in the floater. I talked to them and the PB and told them I was testing pH higher every time I would test and they would be testing it about 7.6 every single time (they are also using test strips only). This week I had them add some MA to drop pH down. I tested within a few minutes of him adding MA which doesn't mean much but it was closer to 7.2.

I showed them the "scale" and the pool guy was pretty sure it wasn't calcium as it can be rubbed off with a finger but it doesn't seem to come off with a rag or pumice stone. I have another picture that shows a bunch more. In any case, the pool guy says he isn't sure exactly what it is but he thinks it might be plaster that dried, not sure how accurate this is though.

I have a digital salinity tester that shows pretty close to what the pool store showed, I do not have a K-1766 but I can order, if needed.

I was told the SWG should NOT be working right now because of the temperatures but every day I have checked the generator, it says "generating." The PB left it at 100% and told me it shouldn't be working so it wouldn't matter, when I noticed it always is generating during the time the pump is on I dropped it down as low as the dial would go because they are using chlorine tabs.

 

[mknauss]

Your profile shows you have a T3 Aquarite SWCG. Check that. If so, it is too small for your pool volume and location. You will need to tun the pump 24 hours per day and near 100% SWCG setting during the summer. You need a minimum T9. Preferably a T15.

 

[Agrabah]

Your profile shows you have a T3 Aquarite SWCG. Check that. If so, it is too small for your pool volume and location. You will need to tun the pump 24 hours per day and near 100% SWCG setting during the summer. You need a minimum T9. Preferably a T15.

I mentioned this to the PB during install and they said they always install this in smaller pools. It's rated to 15,000 gallons. Spoke to several people including the general manager. They all said it would be a waste of money to get a larger salt cell.

EDIT: They also didn't say anything about having to run it 24 hours, they said 8 hours/day max. I've had this discussion with several pool professionals already. Most likely will end up replacing it with a T9/T15 whenever it needs to be replaced, unless during the Summer what you said ends up being the case in which case I will have the PB swap it out for a T15 which should only be about $400 difference, if that.

 

[PoolStored]

I mentioned this to the PB during install and they said they always install this in smaller pools. It's rated to 15,000 gallons. Spoke to several people including the general manager. They all said it would be a waste of money to get a larger salt cell.

EDIT: They also didn't say anything about having to run it 24 hours, they said 8 hours/day max. I've had this discussion with several pool professionals already. Most likely will end up replacing it with a T9/T15 whenever it needs to be replaced, unless during the Summer what you said ends up being the case in which case I will have the PB swap it out for a T15 which should only be about $400 difference, if that.

What @mknauss is getting at is this--> The T3 generates .6 lb/day of chlorine, which in a pool with 10,800 gallons, and a pump running 8 hrs per day will only create 2.2ppm of FC. For comparison, here in OHIO, during the summer, my pool will USE 4-5.5ppm of FC on a daily basis, even with CYA at 70. Being in LV, your sun is worse than mine.

Running 24 hours a day will raise/add FC by 6.7...and that is with THEORETICAL computation. Many of the cells don't put out totals that match specifications.

As a result, we recommend that you install cells that are at least 2x the size of your pool. That does a few things. Allows you to run your pump less. Lengthens the life of the cell. If it doesn't need to be on 100%, say 50% is fine, you doubled the time lifespan of the cell. It also allow for enough production to cover days where you have a large FC day...like a pool party with lots of people (if you can't make more than 6 in 24 hours, and you have a pool party that consumes 9, you then have to revert to adding liquid chlorine to keep your FC levels up).

Hope this helps!

 

[Agrabah]

We are getting off topic but I appreciate the input. How did you come up with the amount of chlorine it will generate? I can take this to the PB as well and see about having them swap it out now then. That's pretty crazy though, they are a large nat'l builder and do a lot of pools a year here so this is surprising they would mess this up.

 

[PoolStored]

How did you come up with the amount of chlorine it will generate?

Look at quick specs or full specs.

Hayward Aquarite SWG - Further Reading

www.troublefreepool.com

Hayward T-Cell-3 Replacement Salt Cell for Saltwater Systems

www.discountsaltpool.com

 

[PoolStored]

How did you come up with the amount of chlorine it will generate?

Use PoolMath. It is the fastest way.

Or this:
Knowns
1ppm = 1mg/L
1oz/Gallon = 7489.15 mg/L
Pool size = 10,800 Gallons
Cell output = .6 lb/day of chlorine (from links above (using discountsaltpool number))

So take the production convert to oz/day
.6lb/day * 16oz/lb = 9.6oz/day.
Then Divide production by total gallons:
9.6oz / 10,800 Gallons = .00088889 oz/Gallon/day
Then convert to ppm:
.0008889 oz/gal * 7489 mg/L = 6.657ppm per day.
Then you can divide that number by 3 to get ppm for 8 hour run:
6.657 / 3 = 2.219ppm in 8 hours.

 

[Agrabah]

So it turns out it wasn't calcium, which makes sense. It's a thin layer of plaster dust that just stuck across the tile. I am going to get a scraper and scrape it all off when it warms up. They suggested cleaning the filter out before hand since the cartridge filters probably have a lot of plaster dust build up from the build.