Is that the usual growth rate? I've had mine for barely 2 months and its went from 3" to 5", but mine is very active all the time not just night and will eat non-stop.
I have found mine to grow fast, but I imagine that growth will slow down around the 8" mark. Feed heavy and do big water changes if you want fast growth.
the clicking noise might be from the electrical organ of theirs. im not sure, but mine does it too with beef heart, and as far as them having a hard time finding food in a larger tank, they seem quite capable of sniffing it out in seconds XD
