The barbs are probably 2 and a half years old now.
I moved them up from the 65 and into the 90 last january, which is coming up a year. So they have been in the 90 for almost a year already. I think I had them for about a year and a half before that. Of course, they were very small when I got them.
they, like normal tinfoils, grow very rapidly (about an inch per month or so) when they are in their growth spurt.