Hi all, A problem pops up while I was trying to calculate the pressure impacts on my aquarium tank walls. The first formula comes up to my mind was: p = d*h where d is pressure at one point inside the liquid d is density of the liquid (assume it's pure water) h is the height or distance from that point to liquid's surface. However, the formula DOES NOT take into account the WIDTH and LENGTH of the tank. To illustrate my problem, i make a comparison between my tank and a test tube. Assume I want to build a aquarium tank (10 x 10 x 10 meters ) and a test tube with the same height 10 meters but with normal radius (about 1 cm) just like normal test tubes. Measurement system does not matter here, the importance is that they have the same height. So if I want to build a tank that's (10x10x10) I probably need to use 3-centimeter-thick-toughened glass in order to withstand the pressure created by that amount of water. However, with the 10 meters high test tube, I just could use a normal glass with much less thin (let's say 1-centimeter-thick is enough right?). So my point is eventhough both have the same height but the aquarium tank requires much stronger glass, compared to the test tube does,to withstand the maximum capacity of water contained. Therefore, I believe the Width and Length ( or simply surface's area) should come in somewhere in the calculation. Can anyone help me point out where i went wrong or what i have missed out? Many thanks in advance!!!