Reef Central Online Community - View Single Post - What is the rational behind keeping odd number of certain fish?

Tripod1404 · 01/03/2018, 12:37 PM

It is a common advice to keep certain schooling and hierarchical fish like anthias or green chromis in groups of odd numbers.

What is the advantage of keeping 7 chromis compared 6 (aside from one extra chromis to deter aggression of course). Or like; Would 7 chromis be better than 8 chromis?

IME for green chromis best number is 1, 2, or 10+. Otherwise there is constant struggle between a small number of fish. I was able to have long term success with a pair and in the past with a school of 20+. But any other number never worked.

For Anthias, it is specie specific and it also depends on the male anthias's ability to keep the females as females. But generally 4 females per male works

01/03/2018, 12:37 PM	#1
Tripod1404 Registered Member Join Date: Mar 2016 Posts: 1,821	What is the rational behind keeping odd number of certain fish? It is a common advice to keep certain schooling and hierarchical fish like anthias or green chromis in groups of odd numbers. What is the advantage of keeping 7 chromis compared 6 (aside from one extra chromis to deter aggression of course). Or like; Would 7 chromis be better than 8 chromis? IME for green chromis best number is 1, 2, or 10+. Otherwise there is constant struggle between a small number of fish. I was able to have long term success with a pair and in the past with a school of 20+. But any other number never worked. For Anthias, it is specie specific and it also depends on the male anthias's ability to keep the females as females. But generally 4 females per male works