Seeding A Filter On A Larger Tank

[P&J]

Quick question about upgrading tank size:

I currently have a 20 gal tank with a cycled HOB filter. I'll be upgrading to a 75 gal soon, but I don't really have the time to cycle it (I want the tank to be set up in my new house before I move, thus making it easier to move the 20g). If I add the fish I currently have to the big tank and run both the new filter and the filter from the 20 gal, will I be OK? On the one hand, I assume so since the bio-load will be the same, but on the other, I'm not sure if the measly 20g filter will process the water fast enough. If this would work to seed the new, big filter, I then plan to move the small filter back to the 20 gal and set it up again. Hope that was clear!

-P

 

[Mikaila31]

I would just take the filter media from the 20gal and put it in the 75gal filter. You can add fish right away when doing this. When you want to move back it may be a little tricky. You could recycle the 20 gal, or you could take 1/4-1/3 of the media from the 75gal to clone the 20gal. Just make sure the 75gal has been running very smoothly for a couple weeks before doing this. Also remember that removing some of the media is similar to adding fish to the tank. You should wait at least two weeks before adding more fish to the 75gal, or taking anymore media.