Finally got my TF-100 . . . CYA low?

Puddinman

Member
Aug 24, 2020
18
McAllen, TX
Got the kit yesterday and ran the gamut of tests it offers. The only thing I was really surprised by is how low my CYA is. Maybe I'm not doing it right but it tested out to below 20. I did it three times to be sure, over yesterday and today. I find that strange because I'm using pucks for chlorination (until I run out and switch completely TFP) and have been for the last 15 years. I have never emptied the pool. I do fill with soft water when it needs a little top up due to evaporation; it's very hot here and that might be every other day or so. We don't have much splash out. I don't backwash my filter (this one is not designed for that).

Since CYA does not evaporate, how is my CYA so low? It's not making sense to me so any ideas out there?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,910
Laughlin, NV
Very low FC.

I bet it rains in McAllen. Have you had significant over flow? How many tablets do you go through in a week?
 

Puddinman

Member
Aug 24, 2020
18
McAllen, TX
We had Hurricane Hannah which dumped a lot of rain, a little overflow with that one. Other than that, some rain but not enough to overflow. I put 5 tabs in the floating chlorinator each week on Sunday.

I'm thinking there almost has to be a leak, no?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,910
Laughlin, NV
With five tablets a week you are adding 14 ppm CYA each week. Things do not compute unless you are exchanging a lot of water to fresh.
 

Puddinman

Member
Aug 24, 2020
18
McAllen, TX
His logs show cal-hypo, not trichlor.
Yes, that’s what I’ve been using to shock. And now to raise FC. I’ll be switching to LC when I’m out of that stuff.
Latest test after adding 6.5 oz cal hypo is at 4.5 FC.

Yeah, I’m guessing I’m losing water somewhere. I figured it was evaporation but maybe not so much. We are going to have the pool replastered very soon so I will have them check for leaks. That will probably coincide with switching to LC for the new fill.
 

Rocket J Squirrel

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Jun 7, 2018
990
Alamo, CA
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Forgive me if I'm misreading this thread. I may be confused.

You say you're using pucks, but cal-hypo pucks are not adding any CYA, and LC won't either. You need to add CYA separately via the sock method or use liquid CYA. When we say "pucks" we more often mean trichlor pucks, which do contain CYA.
 

Puddinman

Member
Aug 24, 2020
18
McAllen, TX
Forgive me if I'm misreading this thread. I may be confused.

You say you're using pucks, but cal-hypo pucks are not adding any CYA, and LC won't either. You need to add CYA separately via the sock method or use liquid CYA. When we say "pucks" we more often mean trichlor pucks, which do contain CYA.
Yes. I haven’t exactly been clear, lol. For the last 15 years, Ive been using trichlor pucks in a floating chlorinator and weeklyish shocks with cal hypo. That was being done by a pool guy for most of that time until I decided “Hey I can do that!” That system worked for the most part unless I got lazy -which was often, lol.

I just learned, believe it or not, about CYA build up and got the test kit to check. I was expecting the black dot to be immediately invisible. Hence the post.

I’m one of those guys who just did whatever the pool store said to do. Then, a few months ago, I discovered this forum and my eyes were opened and I was set free from pool store tyranny. Now I have to figure out why my pool acts the way it does. I appreciate everyone’s knowledge and patience here.
 
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Newdude

Well-known member
Jun 16, 2019
4,823
NY
I’m one of those guys who just did whatever the pool store said to do. Then, a few months ago, I discovered this forum and my eyes were opened and I was set free from pool store tyranny. Now I have to figure out why my pool acts the way it does. I appreciate everyone’s knowledge and patience here
this sentiment has been repeated time and time and time again. Even by some of the folks helping. Everyone gets it, hence their patience because they themselves had to learn to undo bad habits that ‘worked’ until they didnt.

My best advice is to start over completely. It’s hard mentally to accept, but throw out all that you know and start from scratch. All of what is taught here inABCs of Pool Water Chemistry is either drastically different or is completely incompatible with other methods.
 

Ripple

Bronze Supporter
Aug 11, 2020
54
North Georgia
Yes. I haven’t exactly been clear, lol. For the last 15 years, Ive been using trichlor pucks in a floating chlorinator and weeklyish shocks with cal hypo. That was being done by a pool guy for most of that time until I decided “Hey I can do that!” That system worked for the most part unless I got lazy -which was often, lol.

I just learned, believe it or not, about CYA build up and got the test kit to check. I was expecting the black dot to be immediately invisible. Hence the post.

I’m one of those guys who just did whatever the pool store said to do. Then, a few months ago, I discovered this forum and my eyes were opened and I was set free from pool store tyranny. Now I have to figure out why my pool acts the way it does. I appreciate everyone’s knowledge and patience here.
Your situation sounds very similar to mine (I wrote a post on this same topic). While I was not dependent on a pool store so to speak, I did have an independent pool service for the last 5 years (since owning the home). During that entire time, trichlor pucks were used and I continued the same pool service from the prior owners (who built the pool), so I believe pucks were used consistently for 8 years. Once I took over, I immediately stopped and went to liquid chlorine. After receiving my test kit, I was expecting my CYA to be off the charts high. I tested CYA over and over to confirm the results. There have been a few times where subconsciously it's hard to believe the test results, but my pool now looks the best it has in 5 years so I am learning to trust the numbers.

I still don't completely understand "why" my CYA is low given the history, but I did receive some helpful info. Here is the thread: Surprised by CYA test results
 
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Puddinman

Member
Aug 24, 2020
18
McAllen, TX
Your situation sounds very similar to mine (I wrote a post on this same topic). While I was not dependent on a pool store so to speak, I did have an independent pool service for the last 5 years (since owning the home). During that entire time, trichlor pucks were used and I continued the same pool service from the prior owners (who built the pool), so I believe pucks were used consistently for 8 years. Once I took over, I immediately stopped and went to liquid chlorine. After receiving my test kit, I was expecting my CYA to be off the charts high. I tested CYA over and over to confirm the results. There have been a few times where subconsciously it's hard to believe the test results, but my pool now looks the best it has in 5 years so I am learning to trust the numbers.

I still don't completely understand "why" my CYA is low given the history, but I did receive some helpful info. Here is the thread: Surprised by CYA test results
I looked over your thread and I came across that technical article about CYA degradation. I hadn't considered that algae can degrade CYA. That's why I didn't include (as Paul Harvey used to say) the rest of the story.

I've had two really bad algae blooms that happened while I was out cruising for two weeks. One was June 2019 and one was April 2020. Basically, I came back home to a near swamp. Both times, I had already let go of the pool service, but I called them in to help me control it. They cleared the pool and I resumed doing the pucks and dedicated myself to learning more about how to stop this from happening. So here I am, lol! So I'm thinking that those algae blooms (and maybe all the shocking the pool service did) basically ate up all the CYA and I started from scratch in April? I don't know, but I'm sure that's a factor somewhere in there.
 
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Puddinman

Member
Aug 24, 2020
18
McAllen, TX
this sentiment has been repeated time and time and time again. Even by some of the folks helping. Everyone gets it, hence their patience because they themselves had to learn to undo bad habits that ‘worked’ until they didnt.

My best advice is to start over completely. It’s hard mentally to accept, but throw out all that you know and start from scratch. All of what is taught here inABCs of Pool Water Chemistry is either drastically different or is completely incompatible with other methods.
Well, I'm going to start over for sure very soon because we decided to do a replaster. I'm ready to start implementing the TFP method in full once that's done. I'm not going to worry too much about the CYA and such because that process should begin within two weeks. I'll just do my best until then. In the meantime, I added another floater (an old one that doesn't have a lid, lol) with some extra pucks. I will continue to test daily and just ride out that process.
 
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HermanTX

Gold Supporter
May 20, 2020
986
Katy TX
Pool Size
14600
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Plaster
Chlorine
Liquid Chlorine
Hi fellow Texan. Happy that you found the TFP site.
Just curious - prior to doing your own tests, did the pool store test indicate your CYA was low or high?
With TS Beta coming over us, I drained about 8 inches and letting the rain fill back up to dilute my CYA levels. I have been using LC all summer and doing great.
 

Puddinman

Member
Aug 24, 2020
18
McAllen, TX
Hi fellow Texan. Happy that you found the TFP site.
Just curious - prior to doing your own tests, did the pool store test indicate your CYA was low or high?
With TS Beta coming over us, I drained about 8 inches and letting the rain fill back up to dilute my CYA levels. I have been using LC all summer and doing great.
Hello! Yeah, we initially thought we were going to get Beta then it turned to the north. Sorry.

I never got that reading, or it was never something they told me. I only tested in the store a few times. I have actually been testing my own water for a while now, I just didn't have a CYA test until recently. Of course, I never really understood CYA until very recently so if they told me it probably went over my head.
 

HermanTX

Gold Supporter
May 20, 2020
986
Katy TX
Pool Size
14600
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Plaster
Chlorine
Liquid Chlorine
Hello! Yeah, we initially thought we were going to get Beta then it turned to the north. Sorry.

I never got that reading, or it was never something they told me. I only tested in the store a few times. I have actually been testing my own water for a while now, I just didn't have a CYA test until recently. Of course, I never really understood CYA until very recently so if they told me it probably went over my head.
Ok thanks. I don't promote the use of pool store tests but if that is all you had earlier, it is at least a gauge to your own tests. The more you do, the more confidence you will achieve. There are some good articles on CYA testing and also review the U tube videos on TFTests.
CYA EndPoint.png