[Carmen]

Originally Posted by abcha0s

I replaced my ps4 return pump with a new panworld 150ps that I have had on a shelf for the past year. This was not an easy task and required purchasing various PVC fittings so that I could swap the pumps without limiting my ability to switch them back. The result of this experiment is that I still have microbubbles coming from this line.

It occours to me that when other people have replaced their ps4 pumps and had their microbubbles disapear, it could be that they inadvertantly fixed another problem at the same time? There are generally many factors involved in any major changes to plumbing and I think it would be difficult to issolate the pump as the only variable that changed. It is also remotely possible that these owners of ps4 pumps simply had a random defect.

At the end of the day, it looks like my issue may yet be a plumbing one. The only commanality between my three ps4 pumps is that they all have ball valves plumbed on the intake side. These valves are not restricting flow but rather are simply for issolating the pumps from the tank. I have read elsewhere that some ball valves can allow air to be pulled in? While it sounds unlikely, and I did buy good quality plumbing parts, it is about the last piece of my system that I have not issolated.

I am also not convinced this has anything to do with cavitation. My return pump has only 6 inches of straight 1" PVC before going right into the pump. No bends anywhere. There should be no restriction of flow. Further, even when I valve back the pump output, I still have microbubbles. In fact, it may even get worse?

Replacing the ball valves on the pump input will be difficult if not impossible. I will have to devise an experiment to validate the theory before I go down that road. Suggestions here would be welcome.

I am determined to eventually overcome this annoyance.

Please share your thoughts.

Wow...that sorta sucks! I had thought about replacing the pump as well...but perhaps it is not the pump. I do not have ball valves on the input side, only on the output side. Choking back my valves does not help at all either.
I have thought about taking apart the pump, cleaning it well, and cleaning/replacing the tubing so I can see through it to determine if the bubbles are before or after the pump. Kinda a big headache to do all this though...
Thank you so much for noting your results here!