How to build an automatic fishfarm in minecraft!

Build 3 stones like this

Put an upsidedown stair

Set 2 stones like this

And a block on the other side

Set a redstone on the stone block and a redstone torch

Shift click on redstone torch to place a iron trapdoor there

Put water on the trapdoor and tripwire hooks

Connect the tripwire hooks with string

Stand like this under the water and hold right click!

Now its done! i hope you enjoyed the gude!