Get a gravel cleaner. Keep the end about 1" above the sand. Do a gentle figure of 8 to disturb the poo and suck it up. Keep your finger ready to block the outlet end if you go too near the sand and start to suck that up. Stop the flow and allow sand to drop out. Hope this helpsI've not had my sand long i've only done 2 water changes up to now.Please could you advise me on how to hoover the poo up etc?