ok i have a 20 gallon high tank and i got a6 tiger bards 4 normal and 2 albino i had 2 angel fish and 1 gold gourami red gourami and pearl gourami so when i got the tiger barbs i notice that they were attacking 1 of my angels oddly they were only ataking the larger angel its fully grown a koi angel and the middle size 1 was left perfectly alone not 1 attak ever so i removed the koi angel and put it in a gold fish bowl sadly i cant afford to get a tank 4 it but will soon so y are the tigers only attacking the large 1 and leaving the small 1 alone now that theres only the small 1 left the only attaking is the barbs on eachother which is norm and a few non seriouse gourami chases