pH creeping up / how long to run spa spillover each day?


Well-known member
Aug 24, 2017
Long Beach, CA
Have been having some challenges with pH creeping up to 8.4 with my TA at 90.

I am in the process of lowering the TA by cycling through dropping pH to 7.2 and letting it go back up.

Our spa was constantly spilling over into the pool and thanks to one of the sage members on this forum, I was also able to figure (today) out how to enable the Spillover mode on the pool controller.

Now that I have spillover control capability, how long should I run the spillover for each day?
Currently, I've got it set up to run for 3x day for 30 minutes each time.

Thank you!


Well-known member
Jun 13, 2019
Since having a spillover spa, you aerate the water therefore you are getting your pH up faster.
I would go for trial and error until you get to know your pH ups and downs and you will be confident using your spillover feature.


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Currently, I've got it set up to run for 3x day for 30 minutes each time.
Our typical starting point is 2X a day for 30 minutes.

Test the FC in the spa water just before sunset. See if it matches the pool water. Of course, that assumes you are running the Spillover earlier in the day.


Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
Tucson, AZ
3x of 30 minutes is likely plenty if not a little overkill. Just a rough estimate that you likely pump in enough water to completely replace the water in the spa in 10-15 minutes.

To reduce the amount that the actuators have to turn it, I might drop down to two 15 minute periods, maybe once around noon and then again in the evening so that the chlorine is "high" overnight.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Run your spillover 2X or 3X a day for 15 minutes. That is enough to get a fresh batch of chlorinated water from your pool into your spa.

Your spa will lose FC during daylight. So figure it begins losing Cl around 6AM. I run my spillover about Noon and then about 6PM. That refreshes the CL level in the spa during the day.

You can test your spa FC level on a sunny day shortly before the spillover is scheduled to turn on and see how much it differs from your pool FC. As long as your spa FC is not dropping below your target FC level then you are good.