Windelov Java Fern Black Blotches?

[Taregreen]

Can anyone diagnose this issue? I have some Windelov Java Ferns that don't seem to be doing well (see pics). The leaves have black blotches (not spots, but large blotches). I use Easy Green and recently started using Easy Iron, too. I dose in accordance with Aquarium Coop recommendations. I've even started to add a little bit more, just in case. My research tells me that it's a potassium deficiency, but wouldn't they get enough from the two ferts I'm already using or should I supplement with something like Flourish Potassium? Both plants in the pictures are attached to driftwood and not planted in the substrate. 

Thanks!

[Alison]

How long have you had the plant? Is it just melting back and acclimating? When I started my planted tank and I tossed some java fern in, it looked really good for a week or so then I started getting that blotching as well. Most of the older leaves ended up dying back but I have a lot of fresh new growth popping up.

[Taregreen]

About six or seven weeks. I thought it might be melt, but my swords have already melted and have come back. I thought that ferns weren't supposed to melt as bad as swords, so I didn't think is was melt. I'll give it more time to see if they bounce back. Thanks for the reply.

[Garren]

My first guess would be potassium. Once I started dosing extra potassium they perked up. My Java ferns had black spots that would eventually rot and fall out, I did trim some as well then new growth happened. 

[Taregreen]

The only other thing I can think of is too much light? I have a 90g tank with a Stingray 2 LED. The light is on a timer from 11 am to 9 pm. I don't have a par meter so I have no idea if they are getting too much light and getting "burnt" out.