I personally went with the fish in cycling procedure. Used feeders from a local pet shop, they even allowed me to test there water prior to taking the ones I wanted. I kept the fish for about 6 weeks, after which enough ammonia had built up, all the feeders survived and the pet shop was happy to take them back for a refund, knowing well what I needed them for. I have ever since been at a 0 ppm Ammonia, 0 ppm Nitrite, 40 ppm Nitrate. Some say 5 ppm Nitrate is the way to go, I say no to that, as the process is much slower for breaking down the waste, just my two cents, g'luck on the tank, hope your children enjoy for years to come, happy holidays