Are LEGO elements safe to use in an aquarium with fish? I've never seen LEGO elements in a working fishtank.

  • One of our local aquarium shops used to stock the TMC/BrightBricks after-market sets as interesting additions to your aquarium. Commented Dec 1, 2017 at 10:24

2 Answers 2


The main restaurant in the LEGOLAND park in Windsor has quite a lot of LEGO creations in fishtanks. In the same park, the Sealife attraction 'Atlantis Submarine Voyage' has 50 species of sharks, rays and tropical fish that happily coexist with the LEGO models.

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Keep in mind that LEGO is safe from children saliva, which I'm willing to bet is more aggressive than fishtank water.

  • 3
    Not to mention Legoland Windsor's Atlantis
    – Ambo100
    Commented Nov 5, 2011 at 10:35
  • Legolan Billand also has an underwater exhibit with Lego in it.
    – Nathan
    Commented Nov 7, 2011 at 15:22
  • Nice pic. Looks like I have a project. Commented Nov 26, 2011 at 18:19
  • Even if they are safe, will they remain pristine, though, i.e. how do you keep them from turning mouldy?
    – Gnubie
    Commented Oct 20, 2013 at 11:07
  • Not sure about that, but I suppose some cleaner fishes might help - although they might have trouble reaching some places. I'm afraid your best bet there is to remove your creation to clean it regularly.
    – Joubarc
    Commented Oct 20, 2013 at 19:33

LEGO bricks should be safe for fish. Avoid using small parts that they could mistake for food. You also might be cautious on the paint, but I'm sure it's still safer than the paint used on the cheap stuff you'll find at fish stores.

  • 3
    On that note, you may want to settle for normal bricks, perhaps avoid the printed ones. Possibly the older ones (like the old computer screen printed slopes) are less safe than newer ones, and forget any of the stickers. Commented Nov 5, 2011 at 23:29

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