How Long Will Mature Filter Media Last Running In An Empty Tank?

[Harlequins]

I've just attached my new boyu external filter to a empty tank,with intentions of putting 3 corys in it later.

I've added mature media,how long before it starts dying back?

I've got visitors due,will be a bit rude to catch fish while they're here

 

[Tizer]

days

 

[the_lock_man]

If the visitors are staying a week, then you've got a problem. If only a few hours, then no problem.

 

[Tizer]

tbh i've left my fry filter running in an empty tank for 2 weeks and its kicked back into life after only one water change. If you are worried, put a pinch of fish food into the tank or something you know polutes the water quickly, hikari first bites for example.

 

[Harlequins]

Thats great,thanks guys