The black are activated carbon and the white are ammonia chips (I believe that's what they are called). You can continue to use carbon, if you like. Any petstore and Walmart sell a large container of it. Just scoop it out until its' full.
I don't know exactly what that filter is, so I don't know what exactly to recommend.
55gPLANTED:Rainbows/Loaches/Garras|30gVIV:Crestie|20gL:Leos|10g:Pearl Fighter|5g:Betta|5gChi:Spark Gourami/Badis|5g:ADF|2.5g:Betta|2.5g:Betta|