Introducing New To Old?

[jim566]

i currently have 3 bleeding heart tetras and 1 columbian tetra all bought together at the same time from the same tank (he was the only one left) all schooling together until recently after a little makeover of my tank. How would the columbian take to some more being added bearing in mind hes at least 3 yrs older than any new ones i add? if i can find some more that is

 

[backtotropical]

Columbians are known to occasionally be agressive towards smaller fish, so getting smaller ones would be a risk. However, they will shoal with other types of tetra so it need not be a problem. I would try to get tetras the same size as him rather than the same type. Hope this helps.