i actually just upgraded tanks[10 gal to 15 gal,] but i'm in an EXTREMELY tiny space [state college dorm room] so i had no room to run 2 tanks. so i cut corners immensely. here's what i did:
-set up the new tank NEXT TO the old one, shut off the filter.
-pulled out the filter pad [it'd been in there for about a month, very well established bacteria on it.
-i siphoned over ALL of the water from the new tank, and squeezed the old filter pad in it. i let the pad soak in the water while i added new, conditioned water to fill up the tank all the way. i used eco-complete substrate, which is seeded with beneficial bacteria.
-i transferred ALL decor into the new tank, including several live plants, and turned on the filter. when the water started clearing, i put my five skirt tetras into the tank.
none of them showed any signs of stress, and the levels of everything have remained normal.
just to show it CAN be done
