Pression engine

[Gabriele]

Mine, wanted to be only a question to help me solve this kind of problem,because a can't focus the exit. I know,in a cycle where i rise,let fall,compresss a gas or a liquid,there must be always an equal sum of energy used and gained. My is could be an easy exercise for you. Can you help me? I will rewrite the problem if you didn't understand what i wrote. I compress water using x energy + the energy needed to rise the weight of water from the botton. I let expand it laterlally from the same distance i compressed...than i bring she back where it was,down to te bottom. If i consider a recatangle tank of 10x20m,energy i use to compress is a LOT+10kg of force per 10m... when i decompress it energy water should return should be that alot+10kg of force per 10m,,, but in this case i computated is less...always that LOT OF ENERGY+should be 10x10.. but density cannot return 1(medium densiity from 0to 10mof deep)x10(height of the moblie wall)x10(travell) Medium density will pass from 1 to 0.5, so where does de rest of energy come from? From the lower level of the water now stands and doesn't have no more the 10m of water above her so the compression of the water decrease a little permitting this 10-12% of energy to return? 10-12% of the whole is a lot of energy considering water will increase her volume for 1/1000000 c.ca.... if some one can enlight me about this trouble, thanks