I have one of these filters for my drinking water:

It is due to be replaced, can anyone advise how I could 'upgrade' this?
What about one of these:
http://www.ebay.co.uk/itm/10-WATER-FILTER-HOUSING-CLEAR-WHITE-WITH-1-4-PUSH-FIT-/380406807508?pt=UK_Pet_Supplies_Fish&var=&hash=item5892033bd4
and just fill it with activated carbon? Or must I use the specific filters etc?
Thanks


It is due to be replaced, can anyone advise how I could 'upgrade' this?
What about one of these:
http://www.ebay.co.uk/itm/10-WATER-FILTER-HOUSING-CLEAR-WHITE-WITH-1-4-PUSH-FIT-/380406807508?pt=UK_Pet_Supplies_Fish&var=&hash=item5892033bd4
and just fill it with activated carbon? Or must I use the specific filters etc?
Thanks
