Certified GKH Gardening Expert
As with tomato plants, peppers can also suffer from a virus known as leaf curl. This may be what your pepper plant is experiencing, though it could also be attributed to a lack of water or restricted root growth. The following article should help: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-leaves-curling.htm
Now that the plants have established themselves, you should be watering the plants 1-2 times a week for 20 minutes or so. When you water for longer periods, the roots go deeper and you get healthier plants.