My striped raphael nearly died two days ago when he swam into the overflow for my sump filter and wound up lying on the diffuser plate for the wet-dry filter! He is now living in the sump so he can't swim into the overflow again. The reason he was able to get into the wet/dry is because I had to remove the prefilter because it clogged. Is there any way I can keep my raphael out of the overflow so I don't need to worry about him? Thanks.