Poison needs to be super effective against water already, seriously.
this still doesn't make any sense at all. like none.
still, water is thinning out poison, so water should be super effective against poison.
Since when does the type effectiveness chart need to be totally logical? As long as it makes some minor amount of sense, it's fine, and poison being super effective against water because pollution makes enough sense, plenty more sense than some of the other relationships make. --- My NIDOKING brings all the boys to the yard: http://goo.gl/ExAoe