Hi Mesna,

Watering every 5 hours seems a bit much, but we don't know where you live and what your local climate and soils are like.  It also depends upon just how much water is being disbursed to the plants every 5 hours.  When the plants are watered also makes a difference.  Some vegetables can get foliar diseases, like mildew, if kept wet.  Also, when the weather gets hot, watering in a hot sunshine can result in leaf-burn.  Things can get tricky.  It's often best to check the vegetables on a daily basis and assess their individual needs, and hand-water as necessary.  Different types of vegetables need different types of care, water, fertility, etc.  

You might want to check your local library for a good book on growing organic vegetables in your area.  You're obviously interested in fresh, homegrown food.  There's a learning curve over time, but there is nothing better than organically homegrown vegetables!

All best wishes in your new gardening venture.  

Reinettes.