Thousands of litres of sea water are filling tanks at Bristol's new £4 million aquarium.

The saltwater will be used to fill the 260,000 litre shipwreck display.

In total the new attraction on Harbourside will contain close to a million litres of both freshwater and sea water.

But owner Blue Reef has not given an opening date for the attraction, saying it hopes it will open "sometime in November".

The firm had hoped to open the aquarium in time for the October half term.

Tankers, each containing 30,000 litres of sea water drained under special licence from the South Coast, have begun arriving at the Harbourside location.

Fish to fill the tanks will start arriving next week.

The shipwreck display has two levels –on the ground floor visitors will have the impression of walking through a sunken wreck with a tunnel section and giant viewing windows, while on the first floor a team of special effects artists have recreated the view from Bordeaux Quay across to the Arnolfini.

Using a mix of murals and three-dimensional structures the quay includes Prince Street Swing Bridge, the Arnolfini and St Mary Redcliffe among other Bristol landmarks.

The mural is the work of film artist Greg Winter who has worked on Batman Begins, Charlie and the Chocolate Factory, Robin Hood, Clash of the Titans II and two James Bond films.

Blue Reef's Susie Unsworth said: "With the arrival of the sea water the building goes from being a work site to an aquarium-in-waiting. Psychologically it's an incredibly important stage in the building process and means we can all finally get a real idea of what the completed aquarium will actually look like.

"We're all really proud at the high level of theming throughout the building and the Bordeaux Quay area is a real triumph – it was always important to us that the aquarium reflected its location and celebrated the city's architectural heritage."

Once the displays are filled high-tech filtration systems will ensure any impurities are removed and, in the case of the tropical displays, staff will be able to gradually start raising the temperature of the water in anticipation of the arrival of thousands of tropical marine and freshwater fish.

The Wildwalk/Imax site, next to @Bristol, closed in April 2007 after operators revealed it was losing £1.5m a year.

The Imax will now reopen, showing 3D nature films, alongside the aquarium next month.