curious for you rbta or bta owners out there. when covering intakes of powerheads, on the maxijets, there's already a covering for the intake. is this sufficient or do i need to sponge it(id prefer not to) also, are rbta's stings set to kill or set to stun for other corals? if the rbta dies, will it poison the tank and wipe out my livestock? and finally, is a newly cloned rbta for a good deal? Thanks guys.