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 cloudy and mild with occasional rain overnight. Clearer but fresher into Friday
Staying mild but rather cloudy overnight with rain for a time into Friday. Improving to brighter, cooler conditions later. Windy weekend.
A woman from Wirral discovered her husband had secretly married another woman after she saw him kissing his new bride on Facebook.