Is it true a shark won't outgrow its environment?
Furthermore, do sharks stop growing?
Great white sharks need decades to reach adult size, and they continue to grow throughout their lifetimes. So, a much-bigger-than-average shark, like Deep Blue, is likely an older shark. After reaching maturity, white sharks' growth slows — but it doesn't stop.
Secondly, why there are no great white sharks in aquariums? Basically, there are two main reasons great whites aren't kept in captivity: it takes an insane amount of resources for the aquarium to pull; and – most importantly – the sharks die quickly outside of the oceans no matter what zookeepers do.
Regarding this, can you keep a shark in a fish tank?
While it's next to impossible to keep a real shark as a pet, there are plenty of freshwater aquarium sharks that thrive in a home aquarium. They're large fish with shark-like appearances that typically belong to the catfish or carp family.
Will a fish outgrow its tank?
Almost all cold-blooded animals, including fish, will continue to grow as long as they are alive, and may outgrow a small tank. The "full grown" size of a fish is determined by genetics, not by aquarium size, and individual fish will reach different sizes, just as adult humans reach different sizes.