I would assume the brown leaves are dead or dying and won't turn back to green. However, if the rhyzome is healthy new leaves sould start to grow off of it soon.
With that low of a lighting level (not bad for java ferns) I personally wouldn't add ferts, especially if that is the only plant you have. It may take some time for the plant to come back though.
With that low of a lighting level (not bad for java ferns) I personally wouldn't add ferts, especially if that is the only plant you have. It may take some time for the plant to come back though.
