Adult dragons should get 90% of their food in greens and vegetables, with some fruit (but very little on the fruit). A single feeding once a day is fine for each dragon with a few scattered insects. Adding crickets, silkworms, roaches, butterworms, superworms etc to the diet is good to, but try to keep the insect amount no more than 10-20% of their daily intake of food. (breeding/clutching females should get a bit more insects (ie the 20% amount) to help with egg production. THey should also have 2-3 dustings of calcium powder as well. The male and non breeding/egg laying females, are fine with one or two dustings a week of vitamins and calcium D3.
For a good ideal on what greens/vegetables to feed daily and to mix it up for variety, the website below is perfect.
To me dragons shouldn't be bathed at all except to clean them up if they happen to drag themselves into their own poop or are dirty otherwise. A healthy eating dragon will get all the moisture they need from fresh greens. But each dragon is different and if your dragon appears to enjoy the baths (some hate it with a passion) once a week is fine.
As for the amount of food, it really depends on your animals. I suggest about half a cup or so per adult dragon of chopped greens/veggies. More offered to breeding/egglaying females. However, monitoring their weight and condition and adjust amount of food and types of food offered accordingly. A too fat dragon is just as unhealthy as a too skinny one. A healthy weight dragon should look well filled out with a thick tail base and little to a slight roundness of the fat pads behind the eyes.
Posting pictures will make it easier to gauge if your dragon looks underweight, overweight or perfect. Take pictures from above and sides with a good look of the head and tail base.
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PHLdyPayne