decoration from my older 29 gallon tank
currently in my older tank
Hello; That you have an older established tank can save the day. A few choices open to you. First is to rob solid surfaces from the old tank. The beneficial bacteria (bb) form a film on surfaces. Many seem to think only of the filter media as places where the bb colonize, but my take is they will be on many surfaces. Maybe a bit more concentrated in and around a filter due to regular water flow. The bb should be on all surfaces of a filter at any rate. You should be able to transfer most or all the filter media from the old tank into the new setup.
Replace the media in the old filter with new stuff. The bb in and on the surfaces of the old filter will seed the new media and should get the old tank back up to balance soon.
Another way open to you is to rob several hard surfaces from the old tank. Gravel, additional décor and such. These surfaces should have bb on them.
can cycle the tank with fish but it needs water changes every other day as well as prime once a day
Hello; I do not see why a fish-in cycle is needed for you. You have the old tank and can jump start the cycle process or at least speed it up.
The issue with fish-in cycling is the water changes. To protect the fish from ammonia WC are done to keep the ammonia levels low. Low ammonia levels do not promote the growth of the bb so the process is slowed down unless you are willing to allow the fish to suffer.
cynotilapia afra cobue are pretty rare in my area
Hello; You have the old tank. You can hold the new fish to it for a time. This way fish can be to the new setup one at a time. This way the bb populations can be allowed to increase gradually.
Another option is to move the fish from the old tank into the new and add the new cynotilapia afra to the old tank.
Anyway you may not have a big problem. Having an old setup and robbing bb from it is the way I set up a new tank.
One more point to consider. You say you moved the décor into the new tank without fish in it. The fish are to arrive later. The décor or other material from the old tank should not be added to the new tank until you have fish to add at near the same time. The bb need the ammonia and nitrites to thrive. They will not die off for a few days but may go dormant without their needed nutrients. Rob the stuff from the old tank at near the time you plan to add fish.
Good luck