[SuperFudge]

The snapper is too big at full tilt, cut it back to 1/3 or so, the pump is designed to do that and will be fine.

Keep the foam blocks in and run your sump lower...this will make sure NO water spills over the first baffle plate and all has to go under the plate and through all the foam.( therefore getting rid of the micro bubbles that the socks didnt catch)

This will also be your indicator that the foam is getting clogged, as the water in the first section will start to spill over the first baffle...right now its running like the foam is clogged....this is tellin me your flow is way too high, and/or your sump water level is.

Likley when you have the micro socks and your flow is right, you can remove the foam.

If micro bubbles are coming into the third chamber, your flow is too much or water is coming "over" the first plate...or possibly a leak in your intake side of your pump.(seems youve already considered this)

Micro socks on the exit pipes.

You dont need a high "sump to tank" turnover rate...keep it low enouph to provide the tank with adequate surface skimming and thats all, your main tank flow will be provided by "in" tank powerheads or closed loops.

Any pumps or fluval exit lines NEED to be returned to the first or second chamber...not near the intake for the return pump....fluvals constantly spit air.

Try putting an elbow and a small piece of pipe onto the inside of the intake bulkhead, and place the intake to an area of the sump that is less likley to have air bubbles. (usually a corner)

Marc.