Watermelon auto & northern light auto

Everything going well this week, they started to pick up speed and bushing out a little specially the watermelon. They started to show sex very early day 15 NL and day 16 W. They are still quite small and not sure how much bigger they will get from this point on I do not feed the plants at all besides watering them with water from fish thanks. Made some live soil and added horse manure, homemade bone meal from fish bones, compost from vegetable scraps and black soldier fly frass. I do not use chemicals on any of my grows