How much lr do you have? If you are packed with lr and have a good amount of pods, you MIGHT be ok but like the previous poster said, a 46g is really marginal at best.
A sump/fuge would DEFINITELY help. If no sump and not a ton of lr, i think you will have to supplement with live pods fairly often. I have a ton of pods and dont know exactly how many my mandarin eats a day but he is hunting and pecking for them pretty much 24/7.