I like crown loach and I have 10 of them.
Some are 5 inches ( excluding tail ) and the smaller ones are about 2.5 inches.
Can't remember their age, but I'm quite sure the bigger one has been with me for at least 5 or 6 years.
I once have a bluish loach, but they are very aggressive and give other fishes hell of a time.
Thanks for your info, will check out on them.

Cheers!

BT Lee