I use a turkey baster, and blow the algae off---in real extreme cases I use a soft toothbrush--some of my seahorses are ok with it, but others hate it!!!! I have 2 horses that hitch in front of the powerhead and let it blow the algae off of them. The first site of this scared me to death, but I have learned to cope with it!!! They look so funny hanging on getting blown all around, but they really seem to like it.