It looks like you've buried the rhizome of the java fern. It needs to be tied to driftwood, rocks or decorations with the rhizome clear of the substrate or it will die.
Not sure if you missed my previous post, but.....17 W, 24" Full Spectrum <- T8 bulb specs
What type of cories do you have? I'd personally give the giant danio away. They get too big for this size tank and they prefer a school.
I'd get 3 more cories of the same type.