Been running with the Legos for 9 months or so? Can't believe it has already been that long. Thought I would provide a few updates, in case anyone else tries the Lego motif:
1. About once per month I remove the Legos totally to clean them in a bucket with a tooth brush. It takes about 45 minutes to get them looking new again, so they hold up really well in the tank.
2. I have not seen any cuts or scrapes on my fish from the "sharp" Lego blocks (as I have had some people ask me about). I don't think this is an issue.
3. Since taking the Legos out of the tank causes air to get back in the blocks, I have trouble with the structures trying to float. I fixed this issue by purchasing a flat, green Lego square (which you usually use as a foundation for buildings - looks like a grassy yard). I cut the square up into pieces that would fit the foundations of the Atlantis pieces, and attached them to the bottom. This gave me a flat surface on which to pile aquarium rocks and weigh down the Legos so that they won't float. Then I just cover the green part with gravel so you can't see it. Seems to work well.
And I wanted to link over to FailDeadly, who just started a Star Wars tank - looks good:
http
/www.fishforums.net/index.php?/topic/403049-star-wars-tank/