I finished my fishless cycle 2 weeks ago. I have been adding ammonia daily to maintain my bacteria that I had established until my fish were ready to come home. I went to pick up my fish today and ended up having to order another school of tetras as the ones I was waiting on had already been sold. I was going to add them and my platies at the same time. I ended up just adding my platies. My tetras will be in on Tuesday or Thursday. My question is will my bacteria begin to die off in the 2-4 days without having that extra fish load to keep it fed? I plan to test daily to make sure nothing starts going out of whack. But do you think I will have any problem with enough reduction in bacteria to cause an ammonia spike when I add my tetra's? 
