Marco

Thanks, guys! So @tolstoy21, the problem seemed to be the "flow rate of the return pump higher than the rate at which water is making it into the sump" part you mentioned and "balance the inlet flow with the outlet flow" part that @Dandy Pearl mentioned. But there had to be an initial item regarding the filter in the tank to set this mess into motion, which seemed to have blown off all the debris on it into the tank itself. The tank looked like brown soup for a while there, then finally settled down. We did a gravel clean and 30% water change to get things cleared up in there. All fish seem fine and healthy today. Whew! We're a hiring a commercial/residential aquarium consultant to come out tomorrow and give us an assessment and tutorial on our set up. Thanks again to all for the advice! Us newbies really appreciate it!

Thank you, that was very helpful! It seems we have solved the issue for the time being as you mentioned, but will keep an eye on it. Thanks again!

Hi Kyogadude! Here's a pic of the return pump and tank that Traci was talking about. The red line is where the water level drops to now every time we fill it. Any advice you have is greatly appreciated! Marco