Yeah that is a very good example of murphy's law LOL. But as far as the aquarium goes I planned on using a oak style cabinet with no individual legs. And that is a very valid point about the floor boards worping or bowing around the edge of the stand.Hmmm, all of this for my pacu fish. Haha, well the joist span parallel to the aquarium about 10' and are spaced 10" apart from one another. But over all if i just focus on the area around the aquarium rather than the whole floor I should be ok? Is there a type of wood you would recomend using for sistering and possibly the post that works the best? Thanks again for everyone's help and fast response's, I just want to make sure i do it right the first time and hopefully the last LOL.