Some people like to use light cyces when breeding for kepping them its not neccersary. Yes, you can only use flexwatt it is the same as a uth basicley. A tub setup refers to a setup using a rubbermaid container of a good size. It is the setup used by most breeders and Expert keepers. Balls seem to feed more readily and be less stressed out in that setup. I will be moving mine to a tub becuase they also keep humidity and heat better. Hopefully someone will put up some pic of thier tub. MAbey RAB will help?