Pool won't clear up!

Desire5292

Well-known member
Apr 30, 2019
46
Sylvan Springs, Alabama
Some background first... I discovered TFP this spring and opened my pool right - using TFP methods and a TF-100 test kit. Over the course of the summer, I've gotten lazy about it...quit testing regularly, just added chlorine every couple of days, etc. I'm aware that was a bad idea and obviously that's why I'm in the mess I'm in now! Which is: a couple weeks ago, the pool started gradually turning green. I backwashed the filter, brushed the pool, added a gallon of 12.5% chlorine, and have repeated that over and over...it's steadily gotten worse and is now pretty dark green. Stupid me, I didn't think to test it (DUH!) until today, and everything's off.
FC 0
PH 8.2
TA 60
CYA 0 (or at least less than 20)
I didn't check CH because I have a vinyl liner, someone correct me if I'm wrong and need to test it.

I have two questions: First of all, I thought the whole point of TFP and using liquid chlorine or bleach is because chlorine pucks have too much CYA, and it builds up in the pool because CYA doesn't evaporate? I've added CYA to the pool twice this summer (if I remember right, I got it up to 30 the first time and 50 the second). Now it's at 0 again. Just wondering if I misunderstood or did I somehow mess it up by not regularly maintaining and testing everything?
And then...do I need to adjust all the levels or just add CYA and SLAM first?

Thanks!!
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,796
Pleasanton, CA
Several things can lower CYA. The first is splash out but you would need a lot of that to get close to zero. CL will degrade CYA albeit very slowly but is related to FC levels so the higher the FC levels (SLAM), the faster CYA degrades. Higher temperatures degrade CYA faster.

 
Last edited:

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
You need to lower the pH, increase the CYA to 30ppm and then follow the SLAM Process.

No where in the TFP method does it say you do not need to test ... it is quite the opposite ;)
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,410
Franklin, NC
With no FC and no CYA there may be an AMMONIA issue on hand which means slam away to overcome it all.
Too late in the season to really be an ammonia issue. Ammonia tends to be an early pool season problem as the organisms that convert CYA to ammonia seem ot like cold water..

The OP has identified his problem, no testing and insufficient chlorine.

The SLAM is the right answer!
 

Desire5292

Well-known member
Apr 30, 2019
46
Sylvan Springs, Alabama
Thanks!!! Yes, I'm aware it was pretty dumb to quit testing. 🙄 I took on a bit more than I should have this summer and the pool suffered for it! I've learned my lesson! Lol.
Can someone remind me how to lower PH? And with my pool losing CYA so fast, would it make sense to use some regular granulated shock (along with the liquid chlorine I already have) to boost both the chlorine and CYA levels?
 

cubbieblue

Member
Apr 18, 2017
21
Lake Zurich, IL
I test FC daily or twice daily with use. Ph daily. Once a week I test TA and CYA. Takes 5 min or so.
You must know your cya for chlorine adds. Pool math and chart will give different results given different levels of cya.
I'd test for cya again, add appropriate amount, and start slam based on cya level you are shooting for. Cya can take a few days to register on test kit so just continue slam and recheck cya in a couple days. You can then adjust your chlorine adds based on actual cya levels. May need to adjust cya again too. I go low with cya adds and tweek as needed. Get the slam started though!!!!!
 

cubbieblue

Member
Apr 18, 2017
21
Lake Zurich, IL
I'd just add cya based on pool math app. Then bleach at correct level. Cant be more affordable than that. Keep it simple and cheap!
I've added cya 2-3 times this year. Never at 0. But rain. splash out and top offs all change it a little. My range has been 30 to 50.
If you test consistently, you will likely not see a 30pt drop in cya in short time frame.
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,410
Franklin, NC
Thanks!!! Yes, I'm aware it was pretty dumb to quit testing. 🙄 I took on a bit more than I should have this summer and the pool suffered for it! I've learned my lesson! Lol.
Can someone remind me how to lower PH? And with my pool losing CYA so fast, would it make sense to use some regular granulated shock (along with the liquid chlorine I already have) to boost both the chlorine and CYA levels?
Use muratic acid to lower pH. Use Pool Math to calculator how much you need.

Just as an aside, do you have a pool autofill?
 

Desire5292

Well-known member
Apr 30, 2019
46
Sylvan Springs, Alabama
Yeah, after researching, I think all the water replacing has been a huge factor. Besides backwashing the filter, I've had to add water to the pool about once a week (I guess it evaporates a lot in the sun?). Not sure what a pool autofill is...lol.
Can someone tell me where to find muriatic acid? I've never had to use it before.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,420
Laughlin, NV
Stores with pool sections have it there typically. There are normally two strengths, 31.45% and 14.5%. Price is about the same. If you are going to need only add MA every once in a while in smaller quantities, then get the 14.5%, it is less fuming. But if you need MA a lot, like my pool, get the 31.45%.

Muriatic acid should not be stored inside a garage, shed, etc. Fumes from it will corrode metals. I have a 20 gallon Rubbermaid plastic trash can with lid that I store my MA in. Away from any metals.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
replacing water after evaporation will not lower the CYA level, because only the pure water evaporates. The CYA would be left behind, like salt would.