PS4 Making Micro Bubbles

[abcha0s]

I have 3 Poseidon PS4 pumps and I am currently fighting a battle with micro bubbles.

1 PS4 for sump return
2 PS4s for closed loops

I do not believe this has anything to do with my skimmer. Simply put - when I turn off the skimmer, nothing changes.

I have managed to make some improvements, but have not solved the problem yet.

I have taken all of the 90 degree elbows out of my plumbing. I had to leave one 45 about 10 inches before entering the display tank.

Originally, I had not used an o-ring lubricant. I opened all of the PVC couplers and used a Silicone lube. (no comments about algae - that's just silly)

http://www.jlaquatics.com/phpstore/s...t_ID=uv-papsil

I broke down the pump, cleaned it with vinigar and also lubed the pump o-ring.

I used an aquarium safe glue and went all around the outside of all PVC joints. I have heard that they can suck air in through micro fractures in the PVC cement but will not leak.

Tighten all couplers with a pipe wrench. Obviously not so tight that something might break.

Using my return pump as an example, the pump is now about 6 inches from the water source through a straight 1" PVC pipe. On the outflow side, it is a straight run to a 45 degree elbow and then straight into the tank. I still have micro bubbles?!

I have heard other people state that this is a design flaw with the PS4 pump and that it is impossible to stop it from caviating. I am still hopeful to find a solution

I have learned some things in researching this problem that unfortunately I can't fix.

* Always use primer when working with PVC. I didn't use it and now regret not taking the extra time.
* Use 1.5 times the diameter for any plumbing on the intake. For a PS4 with 1" intake, you really should use 1.5" plumbing. Any restriction at all can cause problems.


Any more suggestions? - Please help!