Pat, it all depends. With soaker hoses, it takes awhile to get much water to the soil. I water every 2 to 3 days, by hand with a wand on the hose, to my tomatoes and some other
plants. I give about 1/2 inch of water to my tomatoes, differing amounts to different things depending on the size of the
plant. For instance, with okra, which I got in late, I try to water well in the morning, then if it's convenient, again in the evening. I would also water things like lettuce more often, and most leaf crops and cole family crops.
My tomatoes are mulched, my okra is not, as it's still small, though it's time to mulch between the rows I planted in blocks.
Fro tomatoes and
peppers, I poke a finger into the soil up to the second knuckle. If it's very moist, I hold off a day.
Another issue is the soil, though. I know you have some clay, I have very sandy soil. You could get too much water easily, but your
plants may tell you what they need. If they're thriving the way you're going, it could be alright. I'm not sure if there's any reason to water twice a day, but if it amounts to the right moisture level, why not.
plants tend to like to "sip" water, not get drenched, so that could be a good approach.