ev training help

right on serebi it says for ev trainin to +256 atk and + 256 hp for Gallade..

when do i know ive got to 256...

cos when i level up it'll say like for instince
+ 1 hp*
+ 3 atk*
+ 2 def*
+ 1 sp atk*
+ 1 sp def*
+ 2 spd*

*( i made them up )

but what i dont get is when to start counting the ev's
like as soon as i catch a ralts do i add up all the attk and hp ev's ( if i focus on them )
i'm rlly confuesed with this atm so help would be great thanks

Tom.B

https://pokemonbattlestrades.forumotion.com/EV-Training-h2.htm
go here it might help

really theres a whole section devoted to this

if u ev train for 1 lvl u wont be able to see huge defference is stats at one lvl exept if u are 20 lvl and eve in speed w zubat 4 lvl . then u should see a+6 in speed . The ev point dont go away they just gained in a stady way so sont worry