Hi I have a ar980 aqua one tank with factory lighting and a 160L/h air pump with 2 stones on each side of tank, my Java fern has gone black on the edges and couple of my other plants are looking the same i was using flourish but now using flourish excel and help would be appreciated 

Possibly the start of black beard algae (BBA) and common on slow growing plants like Java fern. Very difficult to get rid of. It may be caused by too much light, and/or water pollutants. It could have already been on the plant when it was bought.

Bear in mind, Java ferns also reproduce by growing tiny plantlets off the edges of the wide leaves. Sometimes this makes the edges look weird.

Make sure you have plenty of water movement and excellent water conditions.

The internet has plenty of detailed info on BBA.

Thank you! Water movement is good as my fish like it and last water test was perfect

Hi found out its not black beard

When I had Java fern the leaves were often edged in black.