Fish Help

i really want to know is that how do you make a school of fish with the LBP water pack?

There's a bunch of ways to make a school of fish. What exactly do you want them to do?

I need to make like a triangle form of fish for my upcoming level.And for them just to go strait like a school of regular fish.

You could create the illusion of a swimming school of fish by making one or more wheeled carts suspended high off the water on a platform in the sky with (invisible) winches or pistons coming out from under them and have the fish attached to the ends. If you want the school to pass by continuously you can also set an emitter to emit said cart at a regular, continuous rate.

A more simpler solution could be to set emitters to shoot the fish sideways at a fast velocity, but they would probably end up going too fast to really see them all that well.

Or simplier:
A make an invisible thin wall, glue fishes there and move the invisible wall w/ the fishes with a piston,
B) if you want them going back and forth, do the same thing, but attatch the piston to a loose invisible dark matter, cpture and make the fishes dissapear once they reach their "turning point" and emit a mirrored version in there.

Hope that helps! :)