Red Sea reefer shooting white gunk debris everywhere

[newhere]

Hello my Red Sea reefer G250+ whenever I turn off the return pump for feeding or maintenance or even water changes and I turn it back on stuff like white poop and debris flies everywhere does anyone else have this issue or now how to fix this?? I have been draining water from where the return pump is to hopefully catch it and take it out before but when I turn the pump on it shoots all of the place. I have been putting a filter sock over it to catch it but its kinda tetius with how my set up is with the lid

 

[KrisReef]

I have seen this happen when bacteria start to grow inside the piping. The bacteria slime is dislodged by the water bouncing through the pipe. With any luck, the corals will enjoy the bacteria you have as a meal but I have also seen tanks crash when large cleaning operations have stirred up the bacteria flock that was growing in the system.

Some newer pumps ramp up when they start up, and that might reduce the amount dislodged? Hopefully as this tank matures the problem will fade away?