going through a mini cycle..
 

Replaced by 55g wth new 55g because the old one had some damage. Also switched to sand from gravel in the process. So I lost tons of bacteria there obviously. I was running 2 HOB filters on old tank that I transferred over so I've got some good bacteria. I had majority artificial plants that I also removed in favor of live plants. Amazon sword, 2 crypts, 2 water sprite, java fern and some pygmy chain sword. I already had some vals. Added 2 mesh bags of gravel to help seed the tank . Now to the fish, I have 28 fish, platys, zebra danios, bloodfin tetras, cherry barbs and corys. I switched all this yesterday and tested the water today and got a. 25 ammonia reading 0 nitrite and less than 5 nitrate, some obviously I'm going through a mini cycle with that ammonia reading. How long should I expect this to go on? The old tank had been going for nearly 9 months

Since you did the right things by using the same filters, adding plants and bagging gravel you probably just need to monitor somewhat closely for about a week or so. I think you'll most likely just sail on through, but it never hurts to be conservative and be prepared for a partial water change if necessary, just in case. :-)

I plan on doing a 50% tomorrow since the prime conditioner I use should wear off. Thanks, I knew there would be a mini cycle and knew that I would carefully watch water parameters just wanted to how long to expect it.