Originally Posted by friscuba
Are you thinking about transferring everything? If so I would see little reason for worries. The tank's filter and bacteria colony throughout the tank is handling the current load, the move might "shock" it a bit but if you transfer everything (I'm talking filter, gravel, ornaments, plants, a decent amount of water, etc), you don't lose much in the way of either filtration or bacterial colony (other than what's on the walls of the existing tank). Just feed a bit lighter and go a couple/few weeks before adding new fish and I bet you'd be just fine.
I used to cycle tanks that were run by undergravel filters pretty darned fast just by adding a few pounds of gravel and about a third of the water from an already established tank. If you are moving everything, it should be able to handle the current load in the new tank, but you'd have to be careful about re-establishing the old tank all over again.
If you are transferring a partial load, you'll still be way ahead of the game compared to starting from scratch. Transfer some filter material, do a partial water change from the old tank to the new tank, move some fish (preferably nothing that is touchy), then feed lightly the first several days and build up and give it a bit of time before adding the new fish.
Yes, I plan to transfer everything including the gravel. Of course, since the new tank will be considerably bigger, I will be adding new gravel to go along with the old. Here is what I plan to do. Check me on this to see if it makes sense:
1. Place the new gravel and some de-chlorinated water (about half full) in the new tank.
2. Use the established tank's filter media in the new filter and start the filtration.
3. Transfer the fish to a neutral location using established tank water for a few minutes.
4. Take a little of the established tank water and put it in a bucket. Use that bucket of established tank water to rinse the old gravel just to give it a cleaning.
5. Place the old gravel into the new tank and mix it with the new gravel
6. Transfer the plants from the established tank to the new.
8. Transfer the remaining water in the established tank to the new (although I don't know if this is necessary since I have read that its the media, and other non-water items that carry the beneficial bacteria)
9. Fill the tank with more de-chlorinated water if needed.
10. Transfer the fish to the new tank.
11. Monitor the water for the next couple of weeks, make water changes as necessary.
12. Begin to add new plants and fish once the new tank is balanced.
Does this sound like it will work, or will this generate a new mini-cycle?