My shellos in platinum knows hidden power and I want to know what type it is cuz its not very effective to water and super effective to fire but there is no type that is like that. Help!!
There is a guy in Veilstone City, in the building where you get the prizes. He will tell you what type the hidden power is.
Like DarthDestiny said, the only type that is super-effective against fire but not effective against Water, is Water itself.
It's Water type but I have no idea where you can check it.
Well, Hidden Power's effectivness depends on the Pokemon using it, like in your case a Water-type like Shellos. Since Water-type attacks are super effective against Fire-type Pokemon Hidden Power is super effective against Fire-types and not very effective against Water-types.