Not really a problem but just a question. I haven't added any baking soda to my pool in over 3 months, maybe more. FC is managed by adding 12.5% liquid chlorine with a Stenner Pump/tank combo (FC around 3-3.5 ppm). 15 gallons of liquid chlorine last me 2-2-1/2 months. I try to keep the PH around 7.5 and do this by adding around 7-8 ounces of 20 Baume muriatic acid once a week when it gets up to 7.7-7.8. So the pH gradually inches up during the week. I frequently check the TA and it's always in the 60-70 range, usually closer to 70. I use the K-2006 setup and also a LaMotte unit. They both give very similar results. Don't get me wrong, I'm not complaining. The TA is exactly where I want to be. I just always thought that adding muriatic acid would bring down the TA and require adding baking soda. I checked the fill water out of the tap and it's ph 7.2 and TA of 15. When I started out, I thought that TA of 80-120 was right and I had to add baking soda quite frequently to keep it at 100. Now I have way too much baking soda on hand (not really a problem). The CH remains steady at 200 ppm. I don't use CYA.
TA question.
- Thread starter Bwdonohues58
- Start date
- Jun 22, 2014
- 47,872
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Sounds as if your TA is indeed very close to being in a good, stable place. 
I suspect you're not seeing the TA fall much more because when you do add acid, it's not enough at one time to pull it down.
On a separate note, even though this is an indoor pool, you might reconsider adding just a little stabilizer to buffer the harshness of straight chlorine, say about 15-20 ppm. With no CYA, the effects of your FC of 3 to 3.5 is exponentially much higher than a pool with CYA. Someone like @Donldson can give you better examples of that FC level with no CYA at all. Something to think about.
Happy Thanksgiving!
I suspect you're not seeing the TA fall much more because when you do add acid, it's not enough at one time to pull it down. On a separate note, even though this is an indoor pool, you might reconsider adding just a little stabilizer to buffer the harshness of straight chlorine, say about 15-20 ppm. With no CYA, the effects of your FC of 3 to 3.5 is exponentially much higher than a pool with CYA. Someone like @Donldson can give you better examples of that FC level with no CYA at all. Something to think about.
Happy Thanksgiving!
Sometimes I feel like a bot being called up on Discord.
For the comparison, at zero CYA an FC of 3.0 at a pH of 7.5 is about the same as having 30 ppm CYA (the lowest the k-2006 can measure) and 25 ppm FC. It's much harsher on people, swimwear, finishes, and equipment than a pool following the FC/CYA Levels even at SLAM level.
That said, being that this pool is used for a business I understand there may be rules against using CYA in the water. If this is the case then keeping the FC lower than 3 ppm would be wise.
And to make this post have something to do with the question at hand: I agree that if the TA is steady according to your k-2006 then I would consider it a lucky situation rather than anything concerning.
Thanks Donaldson. I used to keep it below 2.0 FC. But then I read that the CDC recommendation for a hot tub was above 3.0 FC. My Hayward pool heater has 2 settings: pool and hot tub. To get the water to 95 degrees, I have to use the hot tub setting. So I felt that It might be safer to follow the CDC recommendations. Bacteria likes hot water. There are no complaints from PT clients about the chlorine at this level. I have ordered a Hanna ORP unit to see where things stand. I think that if I can keep the ORP level above 700-750, I will feel safe about lowering the FC. Everybody really likes this pool and we are booked solid. But I appreciate all the input I receive from TFP members.