Hi all,
There aren't many bacteria in the water, they are both in the filter and in the biofilm, substrate, on planted wood, moss etc and these are all good sources.
Like Irene says you can seed it from the filter sponge (or ceramic media etc) from the established tank, just swap 1/2 of them over from old to new.
If you only have 1 sponge, wring some of the mulm from it onto the new sponge, that contains the bacteria.
If you've got time (not in this case) and keep planted tanks the best method of cycling is actually to leave the planted tank for a couple of months, by that time the plants are fully rooted, the biofilm had developed and this is then a very stable environment, capable of withstanding the increased ammonia input from the fish addition.
cheer Darrel