I have 3 Large goldfish 1 blk moor, 1 calico shubunkin, 1 white/gold fan tail in my 75G. I switched out one of the magnum 350 filters and hooked up a fluval 405 in its place. This white/gold fan tail seems to hate the grey intake and return hoses in the tank and is attacking them like a pitt bull. I guess grey isnt his color choice and preferred the blk hoses on the magnum 350. he swims by them and all the sudden whips around and rams them its amusing to see. the other 2 fish pay no attention to the hoses. i can hear him splashing water thats what drew my attention to this weirdness he has going on with the new filter. if he keeps it up maybe i will put the magnum back on the tank and take the 405 off. hopefully he will just get bored doing it and leave it alone.