My 3 weeks old maidenhair fern seems to have lost its lush. It was very healthy when I got it. Now, it's strands seems to be dropping and I see some leaves turning yellow and some turning brown. I know that it's solid needs to be kept moist but still not sure how often to water. Sometimes, the pot becomes lighter the next day but the soil 1 inch beneath is still moist. I am watering after every 3 or 4 days but not sure if I am overwatering or underwatering or doing something else wrong. Some of the mature leaves strands have curled and wrinkled leaves and are drying up. Please help !