[Dingo]

A nano takes the same amount of time to cycle as any other tank. Stuff dies and rots at the same rate, no matter how much water you have.

Since it is such a breeze to do a 10% weekly water change (1 gallon or 1/2 gallon, no big deal) don't buy any fancy filtration. 1 to 1.5 lbs of live rock per gallon and good circulation is all you need.

Also, since you will be doing your water changes religiously (right?) there is no need for any additives whatsoever, unless you are keeping stony corals. Then you need to add ca/alk. Some people like to add iodine, but the utility of that is not proven.

HTH