The aquarium was definitely one of the most fun things I did while I visited Toronto. Totally worth it due to the size and number of exhibits and species. It was clean, with ample seating and at the time we visited it was not crowded at all. We spent about 2 - 3 hours or so, but could have stayed longer due to the lots of information provided at the exhibits and also just staring at some of the sea life. I actually wish I had done the tube/tunnel twice. It was also interactive with trying to touch the sting rays, so that was lots of fun too.

I accessed the Aquarium as part of the City Pass, which I would highly recommend due to the savings by the way, as part of a couple in late February/early March. I would also recommended that time of year to visit as there was enough space and no crowds to be able to linger wherever you wanted to go.

There is also a cafe, the location of which was a bit misleading as it was so early on honestly, but there is a lot to explore afterwards.