New Homeowner - TFT-100 Test Results

[chips2002]

Hi, I am a new homeowner with a pool in the Los Angeles area and have maintained the pool since the beginning of 2022. The pool is an in-ground plaster holding ~14k gallons. I have been looking through this forum gaining lot of good information. There are wealth of knowledge on this site . With the summer starting, I am starting to see some green algae growth in parts of the pool.

I have been running the pump (2.5" pipe) for ~5 hours during the winter (1300 rpm) and have increased to 9 hours in the summer (1300 rpm) + 1 hour (2300 rpm). I am using trichlor tablets (one 3" puck per week, increased to three 3" puck two weeks ago) and have been brushing and vacuuming once every couple of weeks. As part of the maintenance, I clean out the skimmer and pump baskets. I have just cleaned out the Hayward Swimclear cartridge filters (qty=4) opening the filter head. The filters were quite dirty.

Overall, the water has been visually clear. I added 2 gallons of 10% liquid chlorine (1 week apart) the last couple of weeks while I awaited arrival of the TFT-100 test kit. The green algae growth is slowing down with brushing every couple of days.

Today, I tested the water in the morning and am getting the following measurements. I have removed the chlorine tablets due to the high CYA reading. I may have to replace some of the water to lower the CYA based on what I am reading here?? I will also have to increase the Free Chlorine (FC) level based on the CYA reading?? The Calcium Hardness (CH) is surprisingly high.

I would like to ask the forum for advice getting the water chemistry to recommended levels. Chemical recommendations would also be greatly appreciated. Thank you!

pH = 8.2
FC = 4 ppm
CC = 1 ppm
CH = 1700 ppm
TA = 220 ppm
CYA = 140-150

 

[PoolStored]

Hey!! Welcome to TFP!!

The issue you are having is the use of pucks. They add CYA. At a CYA level above about 60 (chlorine pools) or 80 (Salt Water pools), it is very difficult to maintain enough Free Chlorine (FC) to sanitize the water. The VAST majority of people that end up here, do so for this reason.

With a CYA level of 140-150, you will have to replace about 75% of your water to reduce CYA to 40. There is no other way to reduce CYA, and you will not be able to kill the algae without reducing CYA. I was in the exact same position when I found TFP.

Here is some recommended reading on draining.

Draining - Further Reading

www.troublefreepool.com

Here is the recommended levels:

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

I would also review this --> Pool Care Basics

If you need inspiration on all the other before you, check this out! --> How Clear is TFP Clear?

 

[Rancho Cost-a-Lotta]

Welcome Chips!

The only thing I have to add is to consider reverse osmosis service. A big trailer with a huge filter is brought in to filter the bad stuff out of the water. Cost varies, but figure $600-$800 in our area. Your CH is real high. This is one value that will continue to rise as you top off the pool with tap water. Try to figure out a way to hook up the fill line to softened water and avoid solid forms of chlorine and you may have to go through this again. I use a portable RV softener (link in sig). @kul may be able to provide you with contact info for an RO service in your area.

Best wishes?

 

[kul]

For sure! I did RO. It was pricey, but it is an alternative to draining and refilling. I only had to replace about 10% of the water which was a relief given our severe drought and continued water restrictions.
After the RO I bought an RV water softener - the same one used by @Rancho Cost-a-Lotta and @mknauss and that has helped with the CH

Here’s my saga if interested. I think the RO scoop starts on page 4.

Ph after water softener First readings

I did my first t-100 testing. Below I have included my readings as well as readings I tried on the standard solutions. Interestingly the standard solution results did not match what was written on their bottles. I was doing the tests as directed on the plastic card and even did most of them...

www.troublefreepool.com

 

[jeffchap]

How did you obtain the CYA value of 140-150? The test only measures up to 100.

Did you perform a diluted CYA test? Just want to be sure, because otherwise your value could be either considerably higher or lower, affecting how much water you need to drain.

 

[chips2002]

Hey!! Welcome to TFP!!

The issue you are having is the use of pucks. They add CYA. At a CYA level above about 60 (chlorine pools) or 80 (Salt Water pools), it is very difficult to maintain enough Free Chlorine (FC) to sanitize the water. The VAST majority of people that end up here, do so for this reason.

With a CYA level of 140-150, you will have to replace about 75% of your water to reduce CYA to 40. There is no other way to reduce CYA, and you will not be able to kill the algae without reducing CYA. I was in the exact same position when I found TFP.

Here is some recommended reading on draining.

Draining - Further Reading

www.troublefreepool.com

Here is the recommended levels:

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

I would also review this --> Pool Care Basics

If you need inspiration on all the other before you, check this out! --> How Clear is TFP Clear?

Thank you for your reply. Yes, the CYA levels are the issue. How did you go about that 75% water replacement is required to reduce CYA levels to 40. That would be about 10k gallons??

 

[chips2002]

Welcome Chips!

The only thing I have to add is to consider reverse osmosis service. A big trailer with a huge filter is brought in to filter the bad stuff out of the water. Cost varies, but figure $600-$800 in our area. Your CH is real high. This is one value that will continue to rise as you top off the pool with tap water. Try to figure out a way to hook up the fill line to softened water and avoid solid forms of chlorine and you may have to go through this again. I use a portable RV softener (link in sig). @kul may be able to provide you with contact info for an RO service in your area.

Best wishes?

The RO service is to bring the CH level down since the tap water is causing the increase? The services seems quite expensive. Is there any other alternative to adding water if I decide to drain the pool?

 

[chips2002]

For sure! I did RO. It was pricey, but it is an alternative to draining and refilling. I only had to replace about 10% of the water which was a relief given our severe drought and continued water restrictions.
After the RO I bought an RV water softener - the same one used by @Rancho Cost-a-Lotta and @mknauss and that has helped with the CH

Here’s my saga if interested. I think the RO scoop starts on page 4.

Ph after water softener First readings

I did my first t-100 testing. Below I have included my readings as well as readings I tried on the standard solutions. Interestingly the standard solution results did not match what was written on their bottles. I was doing the tests as directed on the plastic card and even did most of them...

www.troublefreepool.com

Thank you for your link! I read through and seems like I am experiencing the same type of problem as you. For the RV water softener, what is the production rate in getting better quality water? Could I potentially buy one of these units and fill the pool after draining?

 

[chips2002]

How did you obtain the CYA value of 140-150? The test only measures up to 100.

Did you perform a diluted CYA test? Just want to be sure, because otherwise your value could be either considerably higher or lower, affecting how much water you need to drain.

I did not perform a diluted test. I filled up the pool water to 7.5 mL and added 15 mL of R0013 and shook for ~45 seconds. Then, poured into the vial until I could not see the black dot on the bottom. The vial did not go past 100 CYA so I did a ballpark estimate.

Reading through the forum, I see that I should make a small container of half and half pool and tap. Fill that mix to the label of the CYA squirter. Then, add CYA reagent to the top of the sticker. Pour until I do not see the black dot at the bottom and multiply X2. Would this be a more accurate way to perform measurement?

 

[mknauss]

Would this be a more accurate way to perform measurement?

Yes

 

[Rancho Cost-a-Lotta]

The RO service is to bring the CH level down since the tap water is causing the increase? The services seems quite expensive. Is there any other alternative to adding water if I decide to drain the pool?

The RO service will service two purposes for your pool; it will reduce CYA and it will reduce your super-high CH level. The service will bring those two values to the lower range, so you're starting off fresh. Assuming you don't use solid forms of chorine, CYA levels will not rise (not present in fill water). Since fill water does contain calcium, CH levels will continue rise with evaporative top offs, since CH does not leave the pool with evaporation. This is why I recommend a softened water source for you fill line. CH would remain stable, so no need to exchange water in the future. If you use unsoftened fill water, you'll need to drain down water each season or two depending on the CH of your fill water.

Test your fill water for CH content so you know what you're dealing with.

Thank you for your link! I read through and seems like I am experiencing the same type of problem as you. For the RV water softener, what is the production rate in getting better quality water? Could I potentially buy one of these units and fill the pool after draining?

I have the larger "Park Model." I've been testing it quite a bit recently. My tap water is CH is 125. After flushing, CH is reduced to less than 10 ppm. I get about 1,000-1,200 gallons before levels rise to 50 ppm. That's when I perform the regeneration (flush) service. With current weather conditions, I need to flush every 3-4 weeks. It's a bit of pain, but it's better than having to drain water and rebalance my pool chemistry.

One of our LV members installed an automated softener dedicated to the pool fill line. Cost is less than my RV unit, but it does require power, a drain for the effluent, and electrical.

https://www.lowes.com/pd/A-O-Smith-35000-Grain-Water-Softener-System/5002101387

Here's the thread...you'll find some good info here regarding CH issues:

Calcium hardness super high - planning to drain this weekend but will be on-going issue

Hi friends, this is year 2 with my gunnite pool (pebblesheen coating on top). I tested for calcium hardness for the first time in a few months and its pretty darn high (1300) which isn't surprising because the water here in vegas is hard. I'm planning to drain a portion of my pool. Pool math is...

www.troublefreepool.com

 

[chips2002]

Yes

Hi Everyone,
Thank you all you the responses and feedback. This is a great interactive forum to gain lot of good info.

I retested the CYA using the diluted method and got a reading of 200 (this is with multiplying by 2).

I am planning to do a drain and refill. I will test my tap/fill water for CH content and get back to you all. Thanks again!

 

[chips2002]

The RO service will service two purposes for your pool; it will reduce CYA and it will reduce your super-high CH level. The service will bring those two values to the lower range, so you're starting off fresh. Assuming you don't use solid forms of chorine, CYA levels will not rise (not present in fill water). Since fill water does contain calcium, CH levels will continue rise with evaporative top offs, since CH does not leave the pool with evaporation. This is why I recommend a softened water source for you fill line. CH would remain stable, so no need to exchange water in the future. If you use unsoftened fill water, you'll need to drain down water each season or two depending on the CH of your fill water.

Test your fill water for CH content so you know what you're dealing with.

I have the larger "Park Model." I've been testing it quite a bit recently. My tap water is CH is 125. After flushing, CH is reduced to less than 10 ppm. I get about 1,000-1,200 gallons before levels rise to 50 ppm. That's when I perform the regeneration (flush) service. With current weather conditions, I need to flush every 3-4 weeks. It's a bit of pain, but it's better than having to drain water and rebalance my pool chemistry.

One of our LV members installed an automated softener dedicated to the pool fill line. Cost is less than my RV unit, but it does require power, a drain for the effluent, and electrical.

https://www.lowes.com/pd/A-O-Smith-35000-Grain-Water-Softener-System/5002101387

Here's the thread...you'll find some good info here regarding CH issues:

Calcium hardness super high - planning to drain this weekend but will be on-going issue

Hi friends, this is year 2 with my gunnite pool (pebblesheen coating on top). I tested for calcium hardness for the first time in a few months and its pretty darn high (1300) which isn't surprising because the water here in vegas is hard. I'm planning to drain a portion of my pool. Pool math is...

www.troublefreepool.com

Thank you for providing another option to softened water. I will look into this.

For testing the tap/fill water for CH, I plan to use the same method as testing the pool water. Is there anything I need to consider when testing? Planning to capture a couple of gallons of tap water in a container and use that sample for testing.

 

[Rancho Cost-a-Lotta]

For testing the tap/fill water for CH, I plan to use the same method as testing the pool water. Is there anything I need to consider when testing? Planning to capture a couple of gallons of tap water in a container and use that sample for testing.

Yes, same testing method. The difference between calculating the amount to drain/refill for CYA and CH is that there is no CYA in tap water. When exchanging water to lower CH, the fill water CH needs to be entered in Pool Math to arrive at the end result. You'll need to drain about 75% to get CYA into range.

 

[IceShadow]

You may want to do the CYA test one more time, but dilute 2 : 1 tap water : pool water. Multiply by 3. If it is 200 then it should register about 60-70 on that diluted test.

 

[chips2002]

You may want to do the CYA test one more time, but dilute 2 : 1 tap water : pool water. Multiply by 3. If it is 200 then it should register about 60-70 on that diluted test.

Okay, I will also test the CYA again diluting by 2 and get back to you all here in a few hours.

 

[chips2002]

Here are my results from the test:
1. CH of Tap Water = 144-175 ppm (it was 6-7 drops of R-0012 until it started turning blue)
2. CYA of Pool Water (diluted 2:1) = 180-210 (between 60-70 in CYA View Tube multiply by 3)

Can I refill using my tap water? How much should I drain (how do you calculate % of water to drain)? PoolStored recommended 75% with a CYA of 140-150.

I plan to water my lawn with the water being drained. Is this okay? I haven't watered my grass for months, and it's starting to dry out/turn yellow. Thanks again for your inputs!

 

[chips2002]

I also retested the CH of Pool Water. Below are my results.
1. CH of Pool Water = 1125-1300 ppm (45-52 drops, color started turning blue, but still is pink/blue; stopped adding R-0012, figured CH is out of bounds)

 

[Rancho Cost-a-Lotta]

CH of Tap Water = 144-175 ppm (it was 6-7 drops of R-0012 until it started turning blue)

No need to retest, but in the future keep adding drops until there is no color further change. Don't count the last drop that didn't change the color. With the CH test, you may different shades of blue.

Can I refill using my tap water? How much should I drain (how do you calculate % of water to drain)? PoolStored recommended 75% with a CYA of 140-150.

Yes. Drain as much as you can. A 75% drain will get your CYA to 50 ppm, a good level for a So Cal non-SWG pool. CH level will decrease from 1700 ppm to 550 ppm when refilling with CH 175 ppm water.

I plan to water my lawn with the water being drained. Is this okay? I haven't watered my grass for months, and it's starting to dry out/turn yellow. Thanks again for your inputs!

I'm not sure, but it should be okay?

Draining in the middle of summer can dry and crack the plaster surface. It needs to remain moist, but it's gonna take at least 15 hours to drain 10,000+ gallons (@700 GPH).

Depending on how high the water table is in your area, there is a slight risk of the pool shell popping out of the ground.

See the article on draining for additional info:

Draining - Further Reading

www.troublefreepool.com

 

[Rancho Cost-a-Lotta]

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