I'm also in the same situation as you, man~! 2ft tank/15gal of water only....However, I've spend more coz i dun even have a freshwater tank to startup with
But i do notice one major disadvantage of our nano tank let alone controlling water parameters.... unsightly equipment all over the tank.... imagine a protein skimmer, a power head, the dc fans and the lights~!! I havent even got the filter yet~!! Really a mess man....
After my exams, I'm gonna have another 2ft tank to act as a sump below this current one to (i) double the water volume (ii) Act as filter (mechanical, biological) (iii) place all the unsightly equipment esp protein skimmer in it.
However, I'm still thinking of how to draw water into the sump and returning it back in a foolproof manner....