Looks like you have a clean-up crew - maybe you need a few more janitors.
Let them tidy up the house for you !
Sucking up the sandbed is not so good to do - and if continued - may hamper your sandbed from performing as it should.
Maybe a little more water circulation down near the bottom of the tank will get some of the detritus and crap moving.
Moving is better than just laying down there - and allows for some of the particulate crud to be removed by the prefilter media in your wet/dry.