@Coral reefer - here's hoping we get this Apex all set up and programmed before our vacation! We'll need to make sure you or Erin are around. This is our whole incentive.
That makes sense now that the water may be flowing back through the plumbing when the return pump is off. I just couldn't figure out why it was dumping all this water back in!You should definitely have the plumbing set up so that if the return pump stops it doesn't overflow your sump. I use a good check valve on the return plumbing but more importantly, I have my return nozzles that feed back into the dt, aimed right at the surface of the water. That way very little of the water actually flows back to the sump if it stops. It also gives a good amount of surface agitation which promotes gas exchange.
Most pic are not working