You don't really need to move bacteria from the existing pond, the bacteria are already in the new pond, tank. They're every where. If you put live bacteria into an environment they don't like you won't get any results. The bottleneck is the environment, not adding bacteria.
What you're actually wanting is to reproduce bacteria so you have a big colony ready to handle a fish load. Nitrosomonas bacteria need ammonia, O2, carbon, water movement (to bring food to the bacteria) and a water temp above 68F (75F is best). Pure ammonia from the drug store is the exact same stuff the fish produce (via urea). O2 and water movement go hand in hand, but a trickle tower type filter provides more O2 and therefore is 10 to 30 times better than submerged media (although moving bed is really good too). Baking soda is a good source of carbon, keep KH in the 300 ppm range as Nitrosomonas use a lot. Stabilize pH by adjusting GH. Make sure the media is in the dark.
By adding ammonia in the same amount you expect your fish load to produce you will know the Nitrosomonas colony is large enough when ammonia level drops to 0 and as you continue to add those same ammonia amounts the ammonia keeps going back to zero. So if you add a day's worth of ammonia the ammonia level should be zero 24 hours later.
That takes care of ammonia. Now you need to grow a Nitrobacter colony to handle nitrites. After all the ammonia conversion there should be a bunch of nitrites. But Nitrobacter don't grow well when there's ammonia present, so back off on adding ammonia. When nitrites go to zero you know your colonies are ready. Keep them alive with the same conditions.
Total time is 1 to 2 weeks.
Of course there are other ways to deal with these issues. Low pH and water temp can make ammonia non-toxic to fish. Ammonia can be bound with chemicals. Water changes can be used to flush ammonia.
