In particular, the filtration in small aquariums must be designed so it can not suck up or otherwise dismantle the animals housed inside. (petbusiness.com)
They even made it easy to set up inside the tightest spaces, like small aquarium cabinets. (geekwrapped.com)
But anyways, granted, the Sea Life Sydney Aquarium is a relatively small aquarium (especially if you compare it to, say, the Shedd Aquarium.. (have-clothes-will-travel.com)