Just tested for the first time with the TF-100...CYA is HIGH

saj002

Member
Jun 22, 2017
7
Blue Springs, Missouri
I converted from SWG to chlorine 2 years ago. Never had as many problems with the SWG as I have with chlorine. I have not been able to get my pool clear this summer. I am done going to the pool store so have taken matters into my own hands. Just did the first test with the TF100. I am using chlorine tablets and my CYA is high. Based on what I have read here, the tablets are the culprit. Here are my numbers:

CYA 100
FC 0.5
CC 0.5
TA 170

I entered my numbers on the pool math calculator, and it says to add 145 oz of bleach and 58 oz (by weight) of washing soda or soda ash. Does this sound right? I have never used liquid chlorine or bleach - should i find a pool store that carries it or just buy regular bleach? And where do i get washing soda or soda ash?

And any chance i can have this pool cleared up in the next few days before the holiday??


The water was green when i opened it, but now it is just cloudy. Has not been crystal clear since i opened it for the summer....
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,271
East Texas
I'd seriously consider replacing half the water if possible to be "4th" ready by the weekend, then follow the SLAM procedure. Regular plain old bleach from Walmart. Why do you think you need washing soda or soda ash? You don't list a ph # for us.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,195
Tucson, AZ
I agree.

Replace 50% of the water and then rerun a full set of test results.

If the CYA is reasonable, follow the SLAM process. If you are diligent, you should be able to get the pool mostly in shape by the weekend. But, you need to start replacing water NOW and then be committed.
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,271
East Texas
Regular plain old bleach from Walmart. You'll also need 355 ounces of 8.25% bleach to raise your FC just to target level of 12 for that CYA. Much less reach SLAM level of 39. See why I suggested you do a partial drain?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,397
San Dimas, CA (LA County)
Whoa! Slow down a bit.

First, when CYA reads that high, there;s a good chance it's even higher. Which is why there's Step 8 here Pool School - CYA

You need to SLAM and to do that you need to raise FC to about 40% of the CYA value. If CYA is over 120, your new tester won't even work! I'll cut to the punch line: you need to replace a bunch of water. Probably more than half. If you can vacuum to waste, that would be ideal, because you could try to get all the debris off the floor while you're replacing water.

And if you're going to be replacing a bunch of water, there's no point in treating it one day just to pump it out the next.

Once it's refilled and circulating and mixed, you can repeat your tests, adjust pH and raise FC to shock level for your CYA level. It's all explained in the SLAM article
 

jimmerz

Well-known member
Jun 25, 2012
170
Pittsburgh, PA
Whoa! Slow down a bit.

First, when CYA reads that high, there;s a good chance it's even higher. Which is why there's Step 8 here Pool School - CYA

You need to SLAM and to do that you need to raise FC to about 40% of the CYA value. If CYA is over 120, your new tester won't even work! I'll cut to the punch line: you need to replace a bunch of water. Probably more than half. If you can vacuum to waste, that would be ideal, because you could try to get all the debris off the floor while you're replacing water.

And if you're going to be replacing a bunch of water, there's no point in treating it one day just to pump it out the next.

Once it's refilled and circulating and mixed, you can repeat your tests, adjust pH and raise FC to shock level for your CYA level. It's all explained in the SLAM article
Richard is spot on, vacuum to waste is how I'd get rid of water quickly. Have fun, it'll go fast.
 

saj002

Member
Jun 22, 2017
7
Blue Springs, Missouri
Ok, so I need to drain at least 1/2 the water. I can vacuum to waste, although there is not a lot of debris on the floor of the pool that i can see. Then once the water is replaced and circulated, re-test, adjust PH and raise FC to shock level for CYA. Man, i think i want my SWG back!
 

AftonJeeper

Bronze Supporter
May 11, 2017
1,148
Twin Cities, MN
One thing to remember with a vinyl liner pool is you don't want to go lower than about a foot of water in the shallow end. That should be more than half the water but wanted to make sure you knew that. Good luck!
 

saj002

Member
Jun 22, 2017
7
Blue Springs, Missouri
So, I have removed and replaced what i thought to be about 50% of the pool water twice now. (It does make me nervous when the water level gets that low with having a vinyl liner.) My CYA is still 90. Do I need to do it again in an attempt to get my CYA level down more? I feel like i am fighting a losing battle with the CYA...
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,195
Tucson, AZ
Unfortunately yes you should replace 50% of the water again. Just remember you should only ever have to do this once because now you should understand the CYA build up and avoid the dichlor and trichlor chlorine products.
 

saj002

Member
Jun 22, 2017
7
Blue Springs, Missouri
I understand it now. Ugh. I will never use those products again! Just started 3rd remove and replace. I hope that this time it significantly lowers my CYA so i can get in my pool at some point this summer.
 

Griswald

Well-known member
Jul 7, 2014
646
Hope Mills, NC
Now you know why you had problems with the SWG. Poor chemical advice from dis-interested outside people. Trust only yourself and your approved test kit.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,195
Tucson, AZ
Wait are you running a SWG? If so then I deal you're going to want your cya between 70 and 80ppm, so you may not need to replace too much more water. Although your slam levels will be a little higher.
 

Other Threads of Interest