Overwatered?

hey everyone, I fed my plants last night and today most/all of the leave tips are curling down and only a few leaves are droopy. Plant is in 20gal container and got 3gal of water. Is this a nutrient deficiency or a watering issue and if so, what do I do?

If you overwatered with 3 gallons in a 20 I'll be surprised. Do you let the medium dry between feedings?

It looks fine by the way.