a shark in a 125 for two years is a long time... i keep my sharks in my 75 for a month or two if even that- I know a 125 is a bit bigger but isn't adequate enough for sharks...
Bamboos can reach 3-4 feet and regardless of what people say that sharks grow slowly-bamboos grow realtively fast. I had a 10" marbled bamboo i picked up and had in my 75 for a few weeks and when I took her into work she was 12" long. In a matter of a month. They also require different styles of feeding because of the way their mouth is setup, I had fed my sharks because getting bit by one of them is rare but if you can't get that shark to eat first thing (or if there is a placenta left after hatching when that's gone) it's a goner. As SOON as you see it out of the case you need to shove some food in it's face so it gets the smell, probably won't take it (make sure they are TINY TINY TINY bits of something, fresh crab works great cos it's easy to pull apart for shark) but it gets them interested in food. Otherwise there is a good chance the shark will starve itself... My last shark did that as she was born with a huge placenta left over, tried showing her food and even after the placenta was all gone she wouldn't eat and slowly starved herself to death. What sucks is it happens :(
I would still watch. Seaweed and eggs look really similar to fish, My naso was always trying to munch on my shark and I had to create a barrier between them...
plan on having to do CPR. it's really common in eggs and its part of the reason a lot of eggs come into the stores dead... lack of oxygen movement and getting tangled and stopping their breathing. good luck with the lil dude tho, sharks are amazing, I just don't think they belong in the hobby.... I know I have them but I also work at the monterey bay aquarium and my sharks are hatched at home and then taken there :) it's easier for me because i have a place filled with experts and i've worked with em for 8 years versus trying to do things on my own.... if you have any questions or concerns please lemme know :)