Be wary, in full sun plants which are not hardened off very slowly can go bad quickly, and it is often fatal. The leaves turn translucent, and your goose is cooked along with your pings. Broken sunlight is best from April to July, after which the plants may take harsher conditions, provided there is ample humidity. Keep in mind the relationship: less humidity, less sun, and go slowly. I hardened off my Mexican Pings under translucent shade cloth, inside an open terrarium with criss cross lathe on the top of the tank. After 3 weeks, I removed some of the lathe. After another 2 weeks, I removed all of them. Now my plants enjoy the full morning and afternoon sun, but I screen them from the noon day sun. They might be able to take it, but this way its no worries and I like that. The plants are attaining a thick glowing character, although they lack the color that flourescent grown plants get. The flowers are more vivid though, and the growth rate remarkably better. My average humidity is between 50-60%. The plants do not sit in tray water, but are liberally sprayed in the late morning, and by afternoon the moisture has evaporated from the rosettes. I am using tap water with no ill effects.
My only experiment with the North American temperate Pinguicula was with P. primuliflora which I placed in a shallow tray with the water level just at the base of the rosette and the longer leaves in the water. The plant produced over 15 offsets in last seasons growing, and probably 30 flowers. It was grown in full sun, and was fairly easy to harden off.