Almost 8,000kg of glass are being replaced at Sea Life Blackpool.
Thirteen sharks and more than 300 fish have been removed while the new glass is fitted.
It is the first time in 23 years the tank has been emptied.
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Mostly dry overnight. Rain from the west by the end of Wednesday
A man who carried out the "sadistic" murder of his baby son because he could not stand him crying has been jailed for life.
Seven friends are walking over 150 miles from Crewe to the Stadium of Light to raise funds for Bradley Lowery. They aim to raise over 1500.