So i have a 55g tank that has been set up for about 5 months give or take and it is doing really well. So with my old 29g i plan on setting it up right beside it with a fish bridge connecting the 2 tanks. So i wanted to establish my 29g tank before i put the bridge in place, so i took one of my established aquaclear70's off the established 55g and put it on my 29g to "instant cycle" it and put the new filter on the 55g..gave it a couple days and added a group of 8 cardinal tetras in it... now after about 5 days all cardinals have passed away and my 29g tank is still not cycled... however the fish were dying about one or two a day not all at once so i am guessing i got a bad batch of cardinals. Anyway why didn't my tank cycle instantly? and what can i do to get it cycled successfully?