I've been in the hobby for a while off an on but will be getting a tank with a sump for the first time. Tank delivery is still a couple of weeks out. Let me know if this sounds about right: When doing a water change the return pump and power heads will be off. Tank water should drain into the sump to the bottom of the weir. Sump should fill up to about an inch from the top of the sump (this is provided I filled the tank to these levels). I clean the sand while doing water changes so I'll be pulling from the tank, when done just fill up the tank with new water to the bottom of the weir. Turn pumps back on and the tank and sump will return to their previous levels in a few minutes. Is that correct? It sounds straight forward but I want to make sure I'm not missing anything. Also I assume one can do a water change by removing old water from the sump and then filling the sump back to an inch from the top. Is that correct also? Just want to make sure my assumptions don't flood my home on water-change days! Thanks in advance for your comments and advice!