I would think there are alot of factors: Size & type of clowns, how big your tank is, are you using any anemones for the clowns ( they might/will sting any unsuspecting C-Horse), size of seahorse. Besides, why subject the clowns to a cooler tank temp? I found a better home for my B/W clowns because I did not want them to be cold just for the C-Horses