Thing about the electric bill is
You took the words right out of my mouth!
For one you can have more fish.
You can have bigger fish.
Because you have more water volume, its my belief that your tank will be more stable.
Because you tank is larger, your tank will be less effected by ambient temperature changes which makes for a healthier envoirnment for the fish.
You will be able to have more sand and live rock which will provide more indiginous food to your fish while being more self sustaining.
I think in you can afford a larger tank, it usually better when it comes to salt water.
That said, I am always amazed when newbies to salt water that start with these little nanos and have great success with corals and such. My brother is a great example. No experience and a 20G nano and his corals are thriving. Go figure.
On the smaller tank side, you have less exposure when disaster strikes.
Its easier and cheaper to correct issues with water changes to avoid potential disasters. A large water change in a small tank is much easier to do which makes it easier to people with little experience to have more success without burning themselves out. Rarely do you read a thread in the drygoods for sale section titled " Nano for sale. Leaving the hobby" followed by "due to economic issues, I cant afford my tank anymore".... Its most always a larger system.
