Jungle cacti need a different type of medium to grow.They must not be kept in full shade, full sun, morning shade, or full afternoon sun.During very hot conditions, watering can be done twice a week.
There are some jungle cacti, which prefer full sun for their growth. So if you are selecting a jungle cacti, it will be better to study the growth conditions of the plant beforehand.
Read more at Buzzle: http://www.buzzle.com/articles/how-to-grow-cactus.html