Check Valve in Return?

I don’t think the placement is the problem it’s the lack of the baffle that’s the problem. Once the baffle is installed I would put rubble rock in the baffle. That will break all the bubbles and make this problem go away. I would put at least 1 baffle if not 2. Then there is no chance the bubbles won’t make it to the tank. I would also put them 1.5-2" apart

[quote=“Gotasplinter, post:20, topic:7483”]
Here’s a short video of the tank might be able to see the bubbles at the end

[/quote]

Yup, there are bubbles at the end.

Finally getting around to fixing the sump

Does anyone see any problems with using the flex pipe that comes with a sump when you buy it?

Yes. It can cracked over time as it drys out. I have had this happen before. If you can use spa flex that would be better because you can glue that.