Berlin AquaDom aquarium: Police not seeking suspects over explosion
The explosion in the Radisson Blu hotel spilled one million litres of saltwater, flooding the hotel and nearby streets, Qazet.az reports.
Hundreds of fish died and two people were injured by falling glass.
Inspectors have now declared the building safe.
A police source told local media on Friday there was no evidence the blast in the 15.85m high (52 ft) aquarium was the result of a targeted attack.
They have also taken to social media to debunk a tweet from a copycat account that is asking for the public's help in tracking down suspects linked to the incident.
A tweet from the real Berlin police account says that they "expressly dissociate" themselves from the fake post and have asked people not to recirculate it.
An investigation into the exact cause of the explosion is ongoing but there has been speculation that the freezing temperatures - which dropped as low as -6C overnight on Friday - may have caused a crack in the tank.
Berlin's Interior Senator, Iris Spranger, told the DPA news agency that first signs suggest that the cause was "material fatigue".
US company Reynolds Polymer Technology, which was involved in the building of the tank, has said it will send a team to investigate the rupture but that it is too early to determine the cause.