Pump shutting off and DE coming out of waterfall

[Ezun]

Just yesterday I was staring at my TFP clear pool in amazement at how clear the water is, it always blows my mind how following the simple processes that TFP teaches and preaches can deliver such water clarity when others who spend more time and money struggle mightily to get to this result. And then, just 4 hours later, I could barely see the main drains at the bottom of the deep end. So I’m back, asking for guidance and advice.

The story:
I know exactly where the cloudiness comes from, it’s issue #1: DE being pumped out of my filter And through my waterfalls into the pool. In seconds, the entire pool is cloudy. This has happened to me now 2x and I’ve been racking my brain trying to figure out how on earth it could happen. See the attached photo for the layout of all my pool equipment. As. You can see - the 3 big pipes in the middle bottom of the photo are lines that connect to the main drain and the 2 skimmers. They feed the main pump and the waterfall pump. You can also see that the waterfall pump (on the left side in this photo) pulls directly from those lines 3 main lines and does not pull from water going through the filter. So, how on earth is it possible that DE is getting out of the filter and over to my waterfall pump? What I noticed this time, is that issue #2: the main pump had shut off for some reason. This makes me think that when the main pump shuts off, the waterfall pump is pulling so hard it starts pulling water backwards through the returns, through the heater, through the filter, through the main pump and over to the waterfall pump and viola, we have DE coming out of the filter over to the waterfall pump. This is the only explanation my meager brain can contrive, which tells me that maybe the check valve just above my main pump is bad.

Questions:

1. Stop DE through waterfalls: While I know it’s happening, I think that there should be something stopping the water from flowing the wrong way out of the filter into the waterfall pump (the check valve sitting above the main pump. Would love anyone’s advice here.
2. Stop main pump from shutting off: Why is my main pump turning off?? Just this morning I got up, it was running as scheduled. I was out there brushing and running the robot and then for no apparent reason it shut off. Sometimes this doesn’t happen for months and then it will happen a few times a day. (By the way, we did recently have a power failure if that would give anyone any indication). it’s driving me crazy to randomly notice that the pump has shut off.
3. Test: Any tests you think I should run to make sure everything is working properly?

Thank you for any advice you can give!

 

[ajw22]

I think you are on the right track. The waterfall pump is plumbed in as a booster pump and should never run when the main pump is not running. The pool should have been built with a separate suction line for the waterfall pump.

 

[Ezun]

Any guidance on how to test that check valve near the main pump?
Also, any thoughts on why my main pump is shutting off at random times?

 

[ajw22]

Any guidance on how to test that check valve near the main pump?

The CV has a clear lid. You should be able to see the movement o the flapper with the pump on and off.

Open up the CV and examine the flapper and spring.

Also, any thoughts on why my main pump is shutting off at random times?

When the pump shuts off is there power from the EasyTouch top the pump?

You need to determine if the EasyTouch is shutting off the pump, is the pump losing power, or is the motor shutting down?

When you see the pump shutoff what is on the pump display?

 

[Ezun]

Ok, I finally found some time to post again.
Update on the check valves - they were installed wrong 5 years ago. The flapper was turned to the side and pressing against the sidewall, not in the flow of water. I repositioned them, lubed them up and fired everything up. All continues to work. (i haven’t tested the scenario of turning off the main pump to see if the waterfall pump pulls the water through, which I will do at some point).

I also completely cleaned my DE filter - and that took a bit of time. When I did it I must not have pressed down enough on the pieces that fits on top of the filter veins and when I turned everything on DE was flowing out of the returns. So I shut it all down, took it all apart again, and put it back to together. on the next startup there was a little residual coming out of the returns, but once that cleared It’s been good since.

I still don’t know why the pump is shutting off, although I think it may be due to the Pentair Screenlogic system. When the pump shuts off there are no errors. I think some of the “schedules“ are colliding and causing this and I’m trying to figure out how to set it properly. Anyone a guru on that portion?

I’m attaching a screenshot of my current schedules. My goal is to run the pump from 5a-11p and have the heat pump turn on when the sun hits the pool (10a-6:30p). I can’t find a way to just enable the heat pump itself without setting a “circuit”, so I think they’re colliding because I have it set to pool