If you win the Bug Catching Contest you get a different Evolution Stone each time you play. If you get 2500 Pokeathlon Points you can get a Water Stone.
The best way is to go to the pokeathlon.
get points at the pokeathlon and exchange them at the prize counter ( on the right)
There is not a route 233 on Pokemon platinum.
underground
how do you find a male houndour in pokemon platinum
behind the waterfall in Mt.Coronet
near the safari zone
Yes, you can dig up a waterstone in Pokemon platinum underneath the resort area.
only vapreon
Exchange Blue Shard with the Waterstone. You'll find waterstone in Abandoned Ship, too.
you can get many waterstones underground you just go there by the exporer kit
Dig it out in the underground.
You can buy it at the Cleadon department store
You can find it somewhere or you can go underground and dig it up.
You must evolve the Eevee you get from Celadon City with a Waterstone.
buy the Pokemon platinum book
Poke'athalon
The 151st Pokemon is Mew and is unobtainable in Pokemon Platinum.
no you can't find a torchic egg in Pokemon platinum