"I looked at orchid soil in Walmart and it all has 3 months of fertilizer added. Do you think it is ok to use that for the ferns or is it too much fertilizer?"

It's probably fine. A lot of ferns seem to like richer soil anyway. Just don't add anymore fertilizer. Miracle Grow -- I'm guessing that's what you're looking at -- has never really done a lot for my plants either way, though.

Also you probably want to try higher humidity.

I my humble opinion, I don't think Maidenhair ferns make very good houseplants at all. They eventually dry up like tumble weeds and die no matter what you do. Some plants labled as "houseplants" just aren't geared for indoor life.
Mine died within a month or two and I never bought another one, nor will I again.
Someone on this forum had posted that they even tried growing one directly over a running indoor fountain for the extra humidity, and it still dried up and died.

Billy Rae

I am having Very good results with maidenhair fern in a large plastic pot. I feed it every 3 months with Fish emulsion or when the new fern turns a light green; water it daily from the bottom, placed a plate under the pot and water it with enough water to count to six almost filling the plate the pot sits on; spray it daily with water to cover all the fern shoots. It likes moisture constantly. You should up the plant container size when the fern is not doing well. Otherwise, just do the above. They definitely take some baby sitting plant wise.

I agree I had to mist mine morning and night to keep it from crisping up, I eventually put it in a terrarium where I now don’t need to mist it constantly and its doing fine