The most elementary way to go about doing it would be to use some basic highschool geometry. Treat the tank as though it is a square/cube and then subtract the area/volume of the smaller pieces that aren't actually part of the tank from the area/volume of the square/cube. Kinda like how the area of a triangle is 1/2 base x height (which is the same as treating the triangle as if it was a square and then subtracting the area of the triangle that isn't actually a part of the triangle whos area you're trying to find.)
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Andrew
Check out my tank at http://www.canadianreef.cjb.net/
[This message has been edited by Canadian (edited 12-22-2000).]
[This message has been edited by Canadian (edited 12-22-2000).]