IMO adding water from cycled tanks will not speed up the cycling of a new tank. So for all intents and purposes you have zero biofiltration in your bullhead tank and if you do nothing, it will remain largely zero for a few weeks, during which if you attempt to feed the bullheads, you will just be torturing and killing them.
What you are doing is a clueless roockie approach, which I have been guilty of plenty and it ALWAYS leads to problems, fish suffering and/or fish losses. The smaller the fish and the bigger the tank and the larger the available surface area for the settling by the beneficial bacteria, the higher the chances of success. That's true. With tiny fish, like 1", you may pull it off easier. But all in all, no offence is meant, this is not what I'd expect from someone who has been on MFKer for 6 years now.
I'd recommend rehoming them into a cycled tank. Otherwise, add Ammolock (to detox ammonia) and table salt (to detox nitrite) or Prime or other ammonia+nitrite detoxifiers. Then you could try to feed them something tiny and easy on biofilter, like blood worms, which are hard to remove though if left uneaten, while the removing ups your chances.
For sure you'd benefit from testing the water by an API test tube kit regularly until the tank is fully cycled. In fact, if you don't start doing it immediately, we'd be largely clueless how to help you.
If your bullheads are larger than 1", you got chances stacked up against you thousand or a million to one.
Forgive me please if I sound harsh. I am sincerely trying to give it my best shot but words are not my forte sometimes.
