30 Gallon Filters?

[Kelsyann]

Yesterday I bought a 30 gallon tank, I'm fairly new to fishkeeping and have some questions. I have a 20 gallon filter with mature media already, would my best option be to add that to the tank and get another 10-20 gallon filter and cycle from there? Or would it be better to just buy a filter made for a 30 -40 gallon tank? (I want lots of filteration) Thanks everyone!
Oh and the filter I havr that I could use is a Whisper 20i

Thanks

 

[Kelsyann]

Oh and is there a better kind of hang-on-back filter I could be using besides the Tetra?