Cycling A Stocked Tank For A New Appliance

[quantumnerd]

Well, I came up with a scenario I"ll be facing a bit down the road.

I'm thinking of getting a fluval 305 three stage external filter (linky Fluval 305
But I already will have a full fish tank with a cultured UG filter by then.

And now, for the milllllllion dollllllllar questionnnnn....

How am I supposed to culture the new filter, ditch the old one, and keep the fish alive all at the same time?

I"m pretty sure I just hook both filters up at the same time, wait a couple of months, and then I can completely ditch that UG filter, but I'm not entirely sure.

 

[Honeythorn]

Basically yes. Just set up the new filter in the same tank and leave it alone for a month or three to make extra sure.

 

[SharonCC]

That's about right...I'd wait three months just to be safe.

 

[Rooster]

Just run them together for as long as you can (couple of months, or more if possible) and the new one will get "seeded"
When you first fire up the external, get it running to your liking, then stir up the substrate (sand or gravel etc) this WILL cloud the water, this will be cleared in a short time - and all the loverly goo will get trapped in the new filters media, together with some bacteria... and away we go !

 

[waterdrop]

Yes, I agree that doing it really long, like the two or three months recommended above should get you as close as possible to having the new one be ready to take on the full fish load pretty quickly. I would still think there would be a mini-cycle though because there's still going to be a natural tendency for the bacteria to balance between the two filters, its just that after three months the new filter will be much more mature, so when you take away the old one, the mini-cycle period should be shorter.

Have any of you recommending ever experienced a switchover like this that didn't mini-cycle some?

~~waterdrop~~