Clean up crew and sand cleaning

Hi!



I have a 25g tank.

3 clowns, 8 hermit crabs, 8 snails, 1 very large snail, brittle starfish, coral banded shrimp, scooter benny, coral beauty.



Question about tank cleaning. Should I be cleaning my sand regularly? Only when I find it dirty? Leave it to the CUC?



Whether regularly or once in a while what do I use? I just went from 13 years of FW to a SW tank. I know I can't use the same gravel cleaner on sand that I did in the FW.



Thanks!