all i can say is to play around with run times and frequency for your optimum results. you don't want the roots to stay soaked, but you don't want them to dry out completely either.

ine area of my garden i run the soaker hose for 3 hours every other day during the heat of summer. in another part of the garden i run it for 2 hours every 3rd day. the difference, the soil in one area hold moisture better than the other.

lauratov, I cannot give you specific answers but if all the plants are established, then the tomatoes and peppers, the watermelons and cucumbers and the carrot will have different water requirements (3 different families).
I'd put larger(2x) emitters on the watermelons and cucumbers. On the peppers and tomatoes I'd put smaller emitters(1x). The carrots, I am not sure about. Specifically, branching is very undesirable in the final product so fertilizing is done as a one-time application at the start and the soil is kept at an even moisture content similar to a hanging basket of pothos (a guess at best).
Alternately, you can put all the plants on a program suited to the peppers and tomatoes and give the others supplementary watering with a hose.