Foam in the hot tub?

[Hal3]

The hot tub water includes the pool water. They have been circulating as one for several days. No one has been in either the pool or the hot tub for several days and the heater has been off. I started circulating just the hot tub through the heater and filter and turned on the heater about two hours ago. The hot tub water is very foamy. It has been raining heavily for several days. The pool water is clear but lots of oak twirly bits fell into the pool over the last 24 hours. Do I need to do anything?

 

[YippeeSkippy]

Sometimes adding some calcium helps with foaming.

 

[Hal3]

Sometimes adding some calcium helps with foaming.

Thank you so much for the suggestion! My calcium hardness just tested at 744 ppm so I'm not sure that is what I need. It seems like some detergent or organics got into my pool water but I have no idea how. No people were in the pool or hot tub and no pets use the pool. My best guess is that it is somehow related to the oak trees around the pool and the rain dumping pollen and oak bits into the water. I ordered some silicone-based defoamer and I will try treating just the hot tub next time I use it if it is still foamy.