I like that idea maybe something I’ll do in future. Ya I figured every other water change I would be vacuuming the bed I’m actually making a siphon that will have a filter sock on the end so I can vacuum and get crap in sock while letting the water recirculate back into sump. Figured that would be easiest and quickest way.I will add another wrinkle or two. About using the plumbing for water changes..it is nice to have a dedicated "out" line or t but in reality, you usually vaccum up stuff while doing a water change.
One thing that I never see done but is a great idea.. got it from the fresh water guys. Is to T off your main return line (from the Pump to the tank) and run the line directly to your filter sock chamber. When you want to clean your sump you just close the return line to the tank and open the line to the sock chamber. Then you just scrub a dub dub with the water running and all the crud in your sump runs through the filter socks and can be removed from the system (and does not get pumped to the tank).
Just an idea but it does work wonderfully. Congrats on the new tank!