While "Fish Tank" the movie was filmed in London and Essex, England, UK, the reality show "Fishtank Live" is a separate entity.
For "Fishtank Live" season 4, the production faced multiple location changes. They were "kicked out" of their initial filming locations and had to find a third alternate location. There was also a user request for seasons 4 and 5 to be moved to Stellarton, Nova Scotia, though it's unclear if this was adopted.
Ultimately, it was speculated that Season 4 would likely take place in a warehouse or a commercial/mixed-zoned space, possibly in Nevada or Texas, referred to as "Facility X". There's also a mention of a "Season 2 House" in Cumberland, Rhode Island and a user on Reddit mentioning Albuquerque in the context of a "Season 4 house", but the information provided doesn't confirm it as the filming location for season 4.