End of season chlorine levels

poolcrazed

Member
Jul 23, 2020
22
Durhamville, NY
Hello, I did not know about the dangers of pucks until this season so have removed about 4-5" of water three times this summer but the pool is 24,000 gallons and we now have a local water use advisory so I can not do any more with this. I was able to get it down from 160ish to 100/110 and it has been super clear. I am in the northeast and the water temp is now mid-50's but I have not covered it yet for the winter since we are still enjoying the garden area it is in the middle of.
My question is: at this low water temp, since no one is swimming, do I still need to keep the FC 8-13ish? I have a very old liner with numerous patches and am worried about sustained high chlorine levels. Is there any chance of algae growing at this temp? It also gets basically almost zero direct sun this time of the year.
Thanks so much.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,321
Laughlin, NV
If your CYA is 100+ then your FC of 8-13 ppm is not high.

Yes, maintain the FC based on the FC/CYA Chart. Prior to installing the cover and final winterization, raise the FC to SLAM level.
 

poolcrazed

Member
Jul 23, 2020
22
Durhamville, NY
If your CYA is 100+ then your FC of 8-13 ppm is not high.

Yes, maintain the FC based on the FC/CYA Chart. Prior to installing the cover and final winterization, raise the FC to SLAM level.
Thanks for your reply. I just checked the ALK again and it's at 80 (CYA still at 95/100). Since I have a whole bag of Bioguard alkalinity increaser can I add this without affecting my CYA levels? I don't want to go backwards!
 

poolcrazed

Member
Jul 23, 2020
22
Durhamville, NY
A TA of 80 is on the high side all ready. You do not want to raise it.
I am clearly not used to these new numbers yet! (100-125 range @ Agway). Thank you for setting me straight. If I do ever need to raise it, though, can I use what I have (bioguard balance product) without affecting CYA or something else critical?
 

poolcrazed

Member
Jul 23, 2020
22
Durhamville, NY
I am clearly not used to these new numbers yet! (100-125 range @ Agway). Thank you for setting me straight. If I do ever need to raise it, though, can I use what I have (bioguard balance product) without affecting CYA or something else critical?
PS It's also 80-120 on the pool calculator site- to add to my confusion.
 

poolcrazed

Member
Jul 23, 2020
22
Durhamville, NY
Recommended Levels
What Pool Calculator site are you speaking of?

You can use that baking soda if you ever need to. It will only effect your TA and pH.
Yes, I'll use baking soda in future but I already bought this so figure I'd use it if harmless....