[Melanie]

Your tank is so nice, for appearance I would consider either adding some kind of substrate (even just a thin layer of sand) or meticulously siphoning the detritus, algae, and rock particles daily. I have no substrate in my QT and I have to siphon it thoroughly to keep it from looking "dirty".

I'll defer to someone more knowlegable about whether the tank will cycle again if you add substrate.