Opening AG pool, this is new to me

Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Hi all, first time posting and newish to pool ownership. I have a 28000 gallon AG vinyl pool with sand filter, 1.5hp pump. My pool water temp is about 60. It’s time to get my chemicals going to stop the algae bloom I had last year. I leave pool uncovered all winter and run the pump at night.

Did my tests yesterday:
CYA looks to be 70
Chlorine is 0
Ph is less than 6.8
TA=20
Ch=350

I suspect I need to SLAM to get started but what do I do about the CYA which is a little high but not crazy high? Can I go ahead and SLAM without addressing the CYA at this level? How do I calculate how much chlorine to add? How much of the stuff to increase my ph?

I’m sure this is only the beginning of my questions while I go through this process for the first time.

Last year was first year I owned this house w pool and battled algae most of the season. Used many expensive chemicals from the pool store. Would like to keep it simpler and less expensive this year.
Pool gets minimal use with 2 adults. Pool in full sun location. Thanks in advance for the guidance!
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Aldis, welcome to TFP! :wave: We can help you, but I have some questions first.
- How are you testing your water? Please add that test kit and all of your pool details to your signature.
- How have you been chlorinating all winter? Are you using tabs/pucks by chance?

Yes, we will probably advise you to increase the TA to about 60 and the pH to at least 7.0 - 7.2 in preparation for the SLAM Process. The CYA is a bit high for a non-salt pool, but fine for a salt pool, so updating your signature will help us there. But let's confirm some of those questions first before we get ahead of ourselves.
 
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zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
13,017
Houston, Texas
Hi, welcome to TFP! I would go ahead and drain some water to lower the CYA. You can PoolMath to calculate how much you need to drain for a CYA of 30ppm. Once you refill the pool, adjust pH to 7.2 If your water is clear you can bring the FC up to normal target level using pool math, and run the Overnight Chlorine Loss Test to see if you need a slam. If its murky begin the slam process.
 
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Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Aldis, welcome to TFP! :wave: We can help you, but I have some questions first.
- How are you testing your water? Please add that test kit and all of your pool details to your signature.
- How have you been chlorinating all winter? Are you using tabs/pucks by chance?

Yes, we will probably advise you to increase the TA to about 60 and the pH to at least 7.0 - 7.2 in preparation for the SLAM Process. The CYA is a bit high for a non-salt pool, but fine for a salt pool, so updating your signature will help us there. But let's confirm some of those questions first before we get ahead of ourselves.
Thanks for the reply!

I am using the test kit from TFP.

Over the winter I was using only the pucks, nothing else. But stopped a couple of months ago after I started digging into the TFP posts.

My pool water looks clear as of now, no signs yet of algae.

I think I have added all the info to my signature. I hope it’s there as I am unable to find that page again.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Okay, pucks all winter confirms what I was thinking in that those acidic pucks pulled down your pH and TA. I would stop using them now, especially since they also increased your CYA quite a bit. Let's get your TA and pH back up first. Since both are low, you can use soda ash if you have it. If not, at least get some baking soda in there right away. Use our PoolMath APP to help you with the amount. Since your TA seems to be 20, use a TA goal of 60 for now. Look for the menu item "Effects of Adding Chemicals", that should help.

Let the baking soda mix for about an hour and re-test to see if you made it to about 60. You want the TA somewhere in that 60-70 range right now, and no lower that 50. Once you do that, test the pH again. If it's still very low below 7.0, add some Borax 20 Mule Team® Borax Natural Laundry Booster. Again, use the PoolMath APP to increase the pH from 6.8 to let's say 7.2. Let mix for an hour and re-test.

While the TA and pH chemicals are mixing, remove those pucks right away. Then you can add liquid chlorine (or regular bleach) in an effort to get the FC from zero to about 10ppm for now. Again, use the PoolMath APP. Test again in about 30 minutes to see if your FC made it to 10 ppm. Adjust or add as necessary, but keep the FC at around 10 ppm for the remained of today. Now before you go right into a SLAM Process, I'd like for you to perform an Overnight Chlorine Loss Test tonight to see if you are indeed losing chlorine to algae. If you fail the Overnight Chlorine Loss Test, then the SLAM Process is next. If you pass, then we'll just help you balance everything like normal.

Let us know if you have any questions.
 
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Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Okay, pucks all winter confirms what I was thinking in that those acidic pucks pulled down your pH and TA. I would stop using them now, especially since they also increased your CYA quite a bit. Let's get your TA and pH back up first. Since both are low, you can use soda ash if you have it. If not, at least get some baking soda in there right away. Use our PoolMath APP to help you with the amount. Since your TA seems to be 20, use a TA goal of 60 for now. Look for the menu item "Effects of Adding Chemicals", that should help.

Let the baking soda mix for about an hour and re-test to see if you made it to about 60. You want the TA somewhere in that 60-70 range right now, and no lower that 50. Once you do that, test the pH again. If it's still very low below 7.0, add some Borax 20 Mule Team® Borax Natural Laundry Booster. Again, use the PoolMath APP to increase the pH from 6.8 to let's say 7.2. Let mix for an hour and re-test.

While the TA and pH chemicals are mixing, remove those pucks right away. Then you can add liquid chlorine (or regular bleach) in an effort to get the FC from zero to about 10ppm for now. Again, use the PoolMath APP. Test again in about 30 minutes to see if your FC made it to 10 ppm. Adjust or add as necessary, but keep the FC at around 10 ppm for the remained of today. Now before you go right into a SLAM Process, I'd like for you to perform an Overnight Chlorine Loss Test tonight to see if you are indeed losing chlorine to algae. If you fail the Overnight Chlorine Loss Test, then the SLAM Process is next. If you pass, then we'll just help you balance everything like normal.

Let us know if you have any questions.
Wonderful, thanks so much. This will be tomorrow's project. I've downloaded and subscribed to the Pool Math app, and have played with it a little, very helpful. Also, I believe I have now added my pool info to my signature, hopefully! Thanks to those who sent me the correct link to find that page again.
 
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Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Okay, pucks all winter confirms what I was thinking in that those acidic pucks pulled down your pH and TA. I would stop using them now, especially since they also increased your CYA quite a bit. Let's get your TA and pH back up first. Since both are low, you can use soda ash if you have it. If not, at least get some baking soda in there right away. Use our PoolMath APP to help you with the amount. Since your TA seems to be 20, use a TA goal of 60 for now. Look for the menu item "Effects of Adding Chemicals", that should help.

Let the baking soda mix for about an hour and re-test to see if you made it to about 60. You want the TA somewhere in that 60-70 range right now, and no lower that 50. Once you do that, test the pH again. If it's still very low below 7.0, add some Borax 20 Mule Team® Borax Natural Laundry Booster. Again, use the PoolMath APP to increase the pH from 6.8 to let's say 7.2. Let mix for an hour and re-test.

While the TA and pH chemicals are mixing, remove those pucks right away. Then you can add liquid chlorine (or regular bleach) in an effort to get the FC from zero to about 10ppm for now. Again, use the PoolMath APP. Test again in about 30 minutes to see if your FC made it to 10 ppm. Adjust or add as necessary, but keep the FC at around 10 ppm for the remained of today. Now before you go right into a SLAM Process, I'd like for you to perform an Overnight Chlorine Loss Test tonight to see if you are indeed losing chlorine to algae. If you fail the Overnight Chlorine Loss Test, then the SLAM Process is next. If you pass, then we'll just help you balance everything like normal.

Let us know if you have any questions.
Question about reading the TFP test for TA. On my second drop of R-0009, it turns what I consider “bright pink.” Is that what I’m looking for? Or do I keep adding drops until I see a darker color that I would consider “red”?
This question arises now because this morning I added 2.5 lbs of soda ash (because I had it on hand and my pH is also quite low.) After an hour, the TA test is the same as before the addition of soda ash, ie 20.
pH seems to have come up but still below 6.8.
Seems I should see a more significant change, shouldn’t I?
Do I wait longer and test again?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,037
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Bright pink is typically an endpoint for a TA test. Add more baking soda. Sounds like your pool water was vinegar.
 

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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,037
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Baking Soda = big TA change, small pH change
Borax = Big pH change, small TA change
Washing Soda = big pH change, big TA change. Probably more TA change than you want.

I prefer to recommend baking soda. Soda Ash (Washing Soda) is just a bit too big of a hammer.
 
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Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Hi, welcome to TFP! I would go ahead and drain some water to lower the CYA. You can PoolMath to calculate how much you need to drain for a CYA of 30ppm. Once you refill the pool, adjust pH to 7.2 If your water is clear you can bring the FC up to normal target level using pool math, and run the Overnight Chlorine Loss Test to see if you need a slam. If its murky begin the slam process.
The Pool Math app does suggest draining water and refilling but I don’t see where it indicates how much. I’m on city water so thats important to know. Am I missing something in the app?
 

Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Okay, pucks all winter confirms what I was thinking in that those acidic pucks pulled down your pH and TA. I would stop using them now, especially since they also increased your CYA quite a bit. Let's get your TA and pH back up first. Since both are low, you can use soda ash if you have it. If not, at least get some baking soda in there right away. Use our PoolMath APP to help you with the amount. Since your TA seems to be 20, use a TA goal of 60 for now. Look for the menu item "Effects of Adding Chemicals", that should help.

Let the baking soda mix for about an hour and re-test to see if you made it to about 60. You want the TA somewhere in that 60-70 range right now, and no lower that 50. Once you do that, test the pH again. If it's still very low below 7.0, add some Borax 20 Mule Team® Borax Natural Laundry Booster. Again, use the PoolMath APP to increase the pH from 6.8 to let's say 7.2. Let mix for an hour and re-test.

While the TA and pH chemicals are mixing, remove those pucks right away. Then you can add liquid chlorine (or regular bleach) in an effort to get the FC from zero to about 10ppm for now. Again, use the PoolMath APP. Test again in about 30 minutes to see if your FC made it to 10 ppm. Adjust or add as necessary, but keep the FC at around 10 ppm for the remained of today. Now before you go right into a SLAM Process, I'd like for you to perform an Overnight Chlorine Loss Test tonight to see if you are indeed losing chlorine to algae. If you fail the Overnight Chlorine Loss Test, then the SLAM Process is next. If you pass, then we'll just help you balance everything like normal.

Let us know if you have any questions.
I am pleased to report that I have managed to get my TA and pH to the targets. TA is 70. PH is 7.2. I just added the suggested amount of liquid chlorine (2.7 gal of 10%). I will test my FC in 30 minutes. To perform the Overnight Chlorine test you recommend, is that the “ Chlorine Drop Test” that is in my TFP test kit?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
I will test my FC in 30 minutes. To perform the Overnight Chlorine test you recommend, is that the “ Chlorine Drop Test” that is in my TFP test kit?
The Overnight Chlorine Loss Test is a separate test used to see if an unusual amount of chlorine is expended in the hours of darkness. The OCLT is also used as one of the 3 passing criteria for the SLAM Process. So if you are performing the SLAM Process, continue to maintain the proper SLAM FC level based on your current CYA - see FC/CYA Chart. Once the water is crystal clear and no more than 0.5 combined chlorine, then prepare for the Overnight Chlorine Loss Test as your final test.

For those FC tests, you will use the FAS-DPD (powder & drops) because the OTO viewer is not as accurate. Hope that helps.
 

Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
The Overnight Chlorine Loss Test is a separate test used to see if an unusual amount of chlorine is expended in the hours of darkness. The OCLT is also used as one of the 3 passing criteria for the SLAM Process. So if you are performing the SLAM Process, continue to maintain the proper SLAM FC level based on your current CYA - see FC/CYA Chart. Once the water is crystal clear and no more than 0.5 combined chlorine, then prepare for the Overnight Chlorine Loss Test as your final test.

For those FC tests, you will use the FAS-DPD (powder & drops) because the OTO viewer is not as accurate. Hope that helps.
Yes, I think this helps. I lost a tremendous amount of FC last night. My OCLT shows FC down to 1.05 this morning from 14 yesterday. . If I’m understanding the TFP system I believe I need to SLAM.
CYA still seems to be about 70-75. (hope I’m reading this test correctly) In my reading on TFP it seems sometimes a little increased CYA is ok?? Higher CYA can protect the chlorine and the sun gets brutal here in SC. But maybe mine is still too high? Do I need to drain some water and refill before I SLAM?
I’m off this morning to get more liquid chlorine as I went through quite a few gallons yesterday and seems that trend will continue for a few more days.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Yes, a SLAM Process is in order. A few comments for you:
- How did you arrive at an FC of 1.05? Remember for FC testing with the FAS-DPD, use the 10 ML water sample size with one generous scoop of powder. Then add/count drops until clear. Divide that number in half. Example - 24 drops equals an FC of 12.
- With a CYA of 75 we round up to 80. That requires a SLAM FC level of 31. Do your best to maintain the FC of 31 until you pass all 3 SLAM criteria. Consistency is key.
- We don't normally recommend a CYA over 70 unless you have a salt pool or live in an area with extreme heat and UV during the summer peak months (i.e. AZ, TX, etc). The only way to lower it is by partial water exchange. Up to you if you wish lo exchange water to lower the CYA first which we in-turn result in a lower FC SLAM level. If you don't feel like doing that, just press-on with the FC of 31 for the SLAM.
- When you add your chlorine, test again in about 30 minutes. In the early part of the SLAM Process, you'll find yourself testing a little more frequently to keep-up with the FC drops, but eventually it will hold better and you can spready out the testing. You'll see a pattern.
- Don't forget to lower the pH to about 7.2 BEFORE adding the chlorine to SLAM level. Once adjusted, don't bother testing the pH again until the SLAM is complete.

Good luck!
 

Aldis

Member
Jul 11, 2020
11
Anderson SC
Pool Size
28000
Surface
Vinyl
Yes, a SLAM Process is in order. A few comments for you:
- How did you arrive at an FC of 1.05? Remember for FC testing with the FAS-DPD, use the 10 ML water sample size with one generous scoop of powder. Then add/count drops until clear. Divide that number in half. Example - 24 drops equals an FC of 12.
- With a CYA of 75 we round up to 80. That requires a SLAM FC level of 31. Do your best to maintain the FC of 31 until you pass all 3 SLAM criteria. Consistency is key.
- We don't normally recommend a CYA over 70 unless you have a salt pool or live in an area with extreme heat and UV during the summer peak months (i.e. AZ, TX, etc). The only way to lower it is by partial water exchange. Up to you if you wish lo exchange water to lower the CYA first which we in-turn result in a lower FC SLAM level. If you don't feel like doing that, just press-on with the FC of 31 for the SLAM.
- When you add your chlorine, test again in about 30 minutes. In the early part of the SLAM Process, you'll find yourself testing a little more frequently to keep-up with the FC drops, but eventually it will hold better and you can spready out the testing. You'll see a pattern.
- Don't forget to lower the pH to about 7.2 BEFORE adding the chlorine to SLAM level. Once adjusted, don't bother testing the pH again until the SLAM is complete.

Good luck!
FC of 1.05...maybe that should have been 1.
The more I read in TFP, the more I realize I don’t know. Before I proceed further I now wonder: Is my water temp in the proper range for correct CYA readings? Hovering between 59-61 degrees recently.
Draining water and refilling is daunting bc I’m concerned I’ll simply create different problems somehow.
It will cost me a small fortune in chlorine to maintain an FC of 31 during SLAM, won’t it?? If I’m losing so much, from 14 to 1 overnight—seems like a lot of chlorine and $$ down the drain so to speak. And am I even reading the CYA test correctly??
Not feeling very confident about this project at the moment. Anyone want to trade a AG pool for a hot tub???
 

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