Help my triops are dieing?

i know triops dont have a long life span but i want to make sure im not causing them to die to soon.....they hatched right after xmas ....they keep swimming on their backs til they croak off one at a time......i just have them in a fish bowl with no air pump.....do they need one.....i dont have no sand in the bottom neither.....i get really confused with the info cause ....one web site said they like merky filthy water so i dont have to change the water but i dont think thats true....also they said not to put anything in the tank like plants or other fish things....thats why i didnt put in the sand...