I was on the verge of ordering Aquaspace's Fluoride filtering carafe when I stumbled on this thread - just in time! Thank goodness!
I've known about Doulton filters for awhile so I read the specifics today and saw that they also use activated alumina to filter fluoride. I sent them an e-mail asking if they could tell me why it would be safe to use this for filtering water. I received this very prompt reply:
"Although there is some speculation that a trace amount of alumina can leach from the media to the filtered water, there hasn't been any scientific confirmation of this. However, if there is any leaching of alumina residue in to the water, it would be trapped by the ceramic filter in the final filtration stage. We sell the A-2 (Activated Alumina) filters as a specialty filter that are part of a dual or triple housing system in which always has a Doulton Ceramic Filter as a final polisher, and in itself has the capability of removing micro-contaminants as well as inorganic/organic chemicals and heavy metals. However, this filter alone does not have the capability of high fluoride removal, hence the reason why we also use activated alumina. If you still do not feel comfortable using this filter, try the B-2 (heavy metal/fluoride filter) which is a highly activated catalytic carbon filter. This too will significantly reduce fluoride as well as heavy-metals and arsenic. In any case, the medias that are used in all of our filters are NSF approved and are industry standard. I hope this helps and thank you for your inquiry."