Just keep your media wet and the biowheel wet. Put them in a bucket of tank water. Then take the filter apart and clean it out. Is the water flowing over the top of the filter pad? If it is, then just change the filter pad or rinse it out well. It does go over the intake if the pad is getting clogged. Do you see water in the window to the right of the biowheel? If so, the pad is just getting clogged. You may not even need to clean out the filter itself.
55G Filstar XP3 - 16" Fire Eel
75G Medium Planted - Filstar XP3 Low Light - Established Feb 2006