Ive (at long last) figured out how to use the fluid simulation, but still having problems, the simulation is fine (apart from the fact that it sometimes looks like oil instead of water), the problem is leaking, for some reason there is fluid leaking out of almost all my attempts, ive seen that i need a thicker mesh, but it still leaks out the sides when the fluid is dropped into it. Is there a way to prevent this from happening because i saw examples of fluid sims where they used a thin whine glass and stuff like that, and it doesnt leak out. Please help 
Also, it takes really long to render
well on the fluid sim go under advanced settings and you should be able to change what type it is. i think the options are water, honey, oil. cant remember.
does it leak when you drop it into a box? because ive never heard of that problem before.
also, this question is like answered weekly so just search for stuff like fluid or water.
noidtluom
yes, i think this has been discussed before - you could try increasing the simulation resolution… That affects both the turbulence of the fluid and the thin obstacles.