How long for new filter to build BB

[dsandford]

So my fx5 and media should be here tomorrow or the next day. It is going on my fully cycled 140 gallon. I have someone buying my xp3 off of me and he wants to know when he will be able to pick it up. I was wondering how long it will take my fx5 to build up enough bb before I take the xp3 can off? Thanks.

 

[fishbum]

2 weeks is usually enough.But if you are selling your old filter,just take all the media out of it and put it in the new filter.

 

[Crispy]

x2

 

[KaiserSousay]

2 weeks is usually enough.But if you are selling your old filter,just take all the media out of it and put it in the new filter.

Too easy.
Must be a harder way