when using a 6g kit for fina in this last kit i got they gave me two whatman filters and one coffee filter why so many types and sizes and can someone explain what order to use them in and is the coffee filter needed with the whatman filters , my instructions do not show them using both it seems to be one or the other, and also the bottles are all plastic but the final sterile vile so how can i heat this or does this kit not need to be heated