Help Moving Away From Trichlor Tabs

bohemus

New member
Aug 19, 2020
2
Scottsdale, AZ
Hi All,

New here. Bought a home with an in ground pool. Pool is from the late 70's early 80's, but was remodeled with new pebbletec, in floor cleaning system was updated from the old A&A turboclean to the A&A style 1 heads and collars. replaced the old ball style actuator valve with the new pin style T-valve actuator, replaced old pump with a new Pentair XF VSF pump, and a new Pentair Triton II TR-100 high rate sand filter.

Bought a TF-100 test kit, which has been great. I knew my water would have high CYA since the previous owner exclusively used trichlor tabs. Previous water tests at leslies showed the CYA at around 168. Using the CYA test from the TF-100, the dot disappears well before the 100 mark on the cylinder, so perhaps that 168 is in the ballpark. I had been planning for a full drain and refill this December anyway, but I would like to keep the pool clear through the end of October so we can continue to swim until then.

Here are the TF-100 results:
PH: 7.5
FC: 4.5
CC: 0
CH: 825
TA: 220
CYA: 100+

The water is clear and looks great, no cloudiness or algae. Based on reading through the forums (long time lurker), it would seem I should get some liquid chlorine and try to maintain at least 7.5% of the CYA level, but I'm not sure of a way to accurately get that number since the max on the test tube is 100, and I dont know if the pool store number for CYA is accurate. Also, I've read that the TA measurement is affected by CYA, so not sure how to adjust that number to reflect more accurately.

Any help or thoughts would be appreciated!
 

HeyEng

Gold Supporter
Silver Supporter
Nov 7, 2018
567
Oklahoma City, OK
Hi All,

New here. Bought a home with an in ground pool. Pool is from the late 70's early 80's, but was remodeled with new pebbletec, in floor cleaning system was updated from the old A&A turboclean to the A&A style 1 heads and collars. replaced the old ball style actuator valve with the new pin style T-valve actuator, replaced old pump with a new Pentair XF VSF pump, and a new Pentair Triton II TR-100 high rate sand filter.

Bought a TF-100 test kit, which has been great. I knew my water would have high CYA since the previous owner exclusively used trichlor tabs. Previous water tests at leslies showed the CYA at around 168. Using the CYA test from the TF-100, the dot disappears well before the 100 mark on the cylinder, so perhaps that 168 is in the ballpark. I had been planning for a full drain and refill this December anyway, but I would like to keep the pool clear through the end of October so we can continue to swim until then.

Here are the TF-100 results:
PH: 7.5
FC: 4.5
CC: 0
CH: 825
TA: 220
CYA: 100+

The water is clear and looks great, no cloudiness or algae. Based on reading through the forums (long time lurker), it would seem I should get some liquid chlorine and try to maintain at least 7.5% of the CYA level, but I'm not sure of a way to accurately get that number since the max on the test tube is 100, and I dont know if the pool store number for CYA is accurate. Also, I've read that the TA measurement is affected by CYA, so not sure how to adjust that number to reflect more accurately.

Any help or thoughts would be appreciated!
If you go to this page and read step 8, it will give you directions to test your CYA for over 100. It appears that the best way to deal with this is with a partial drain, otherwise you will be using a LOT of liquid chlorine.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,306
Fletcher, OK
13 FC would be 100 CYA... at 180 CYA you would be closer to 20 FC never going below 15 to 16 FC and that is an edumacated guess on my part... something you really would not want to do for an extended time...

It would be better to use poolmath to find out how much to empty your pool and refill.. This would drop your CYA, CH and TA and depending on your fill water you could be good to go.. If it were me in AZ I would try to hit a CYA of 60 so maybe you can get away with 2/3 drain and refill???

Do you have a salt water generator? If so you could easily get away with 100 CYA and only empty half your water and be good to go... if you do not have a SWG I would highly recommend it as it would be great for you and your pool and the situation you find yourself in :)

Please fill out your signature with all your pool information so we can get a better understanding of what you have :) click settings on the left and go down to signature...

Great job getting the TF 100, it really is a great kit..