Nano tank sump cleaning



I have an Innovative Marine 16 gallon nano. It has two columns to put filtration material. In one column I have chaeto and maiden hair that acts as a refugium. In the other column I have ceramic rings and a small bag of chemipure elite. The tank is about 11 months old now. I have noticed a lot of detritus buildup in the sump area. I have started to clean the sump area when doing water changes but since it is so small I can't get most of it. Would a small cleanup crew help in this area and if so, what should i get?
I try to change out 20-40 gallons a day. I have a hose ran to my tank that fills it from the top and a drain line ran out of my sump so all I have to do is turn on the water and go work on something else around the house. This should give me a full water change (~400 gallons) roughly every two weeks. I can already tell the fish are even more active now with the smaller, more frequent changes. In the tank are a bunch of barbs, black skirt tetras, a handful of rainbow sharks and redtails, CAE, SAEs, leopard ctenapoma, a breeding pair of JDs, a fire eel, and peacock eel. Nox Vidmate VLC There may be others I'm forgetting.