Does my Spa have its own micro-Chemistry(climate) Than my pool?

[PoolAdmiral]

Hello TFPers. We used the spa last night. We had a solar cover to help heat the spa faster. Total time from start of heating was about 3hours until we finished bathing. I noticed the spa was a little murky afterward. It was late so I didn’t test the chemistry. This morning I tested the spa and not the pool since the pump hadn’t come on yet. Result was almost zero chlorine and my PH was higher than my usual 7.8 .

I keep my pool/spa typically around 4ppm and 7.8ph for my 30cya. I know the hot spa water will burn off chlorine and also ph will rise due to the water bubbles from the jets. To prevent the chlorine going to near zero again and water get murky, shall I add extra chlorine before using the spa every time?

 

[mknauss]

shall I add extra chlorine before using the spa every time?

You can raise the FC before use and mid way through add a touch of chlorine.

 

[Mdragger88]

Along with adding additional fc to compensate for your bather load you may want to tweak your run times to correlate with your general spa usage schedule so it doesn’t sit there stagnant all night.

 

[TopJimmy]

Maybe a data point for winter:
I keep my spa at 68 deg with the pump running low speed. It goes higher speed when heat is called for. I run my IC20 for 8 hrs per day at the lowest setting 2%. When I want to get in it takes 2.5 hrs to get it to temperature. Chlorine seems to be fine mostly, but if it trends down below 2ppm, I’ll turn up the chlorinator