Water slowly trickles over our spa's spillway into the pool non-stop

[Fleur]

Hello Everyone,

Few months ago I noticed that our pool would somehow accumulate excess water and I had to backwash in order to bring our water level down to normal. I thought our pool's water leveler broke so I replaced it. Well, it did not help. Then I noticed that sometimes, after a spillway runs for 10 minutes (it is on auto, runs for 10 min every day) the water from the spa would continue to trickle into the pool. One day it was fine, another day it would trickle. Well, right now it trickles non-stop.
We have a separate pump for a spillway/fountains and I just saw that the water was slowly swirling inside of it even though the spillway/fountains were off. Also, it continued swirling even after I turned off our pool pump.

What might be the problem? Thank you!

 

[jblizzle]

I am not sure I fully understand ... water cannot magically appear in your pool requiring you to drain it

If the pumps share a suction drain, I wonder if one pump could be pulling a little water backward through the other pump? Kind of a long shot, but I can not think why water would be moving in a pump that is not on.

Water continuing to trickle from the spa is likely just due to the return valve not fully closing off the spa and a little water is still entering it and thus overflowing out.

 

[Fleur]

I am not sure I fully understand ... water cannot magically appear in your pool requiring you to drain it

If the pumps share a suction drain, I wonder if one pump could be pulling a little water backward through the other pump? Kind of a long shot, but I can not think why water would be moving in a pump that is not on.

Water continuing to trickle from the spa is likely just due to the return valve not fully closing off the spa and a little water is still entering it and thus overflowing out.

I thought because water leaves the spa and trickles into the pool (for whatever reason), our spa leveler tries to keep water level consistent and adds more water into the spa (which overflows into the pool). I maybe wrong, but that was the only explanation I had for this magic
Also, I described it incorrectly when I said that "the water was slowly swirling inside" of our spillway pump. I saw some bubble movement inside of it. This is a short video of how it looks.

There is a video of water trickling into the spa.

I checked the spillway pump in 30 minutes again (after I shut it off), and the bubbles were gone, but water was still trickling from the spa into the pool. Summary: 10 minutes after I turned off the spillway pump I have water tricking and bubbles inside the pump, 30 minutes - only water trickling.

 

[jblizzle]

You have an autofill on the spa with fresh water? That is odd.

 

[Fleur]

You have an autofill on the spa with fresh water? That is odd.

We did not build this pool, so I assumed that autofill for the spa (we do have one there) was coming from the tap. I did not even think that there are other possibilities considering the spa is situated above the pool... is there any easy way to check it?

I will conduct an experiment tomorrow: I will turn off the autofill at the source (will cut water for the pool + spa) and run the spillway -- I just want to see if water will be trickling the same way after I turn it off. I am not even sure it makes a lot of sense, but I'm getting desperate here
This thing is driving me crazy!