Rah sir,
That smell its a good smell, (as bad as it may smell) when you gut pack your feeders, their stomachs have partially digested food. All that food in their stomachs is what smells, if the fish tank itself smells bad than this is not the case. The reason store bought feeders dont smell bad is, petstores rarely keep feeder fish long enough to be worth feeding, hence the skinny feeders vs. your plump feeders, Nothing is wrong with them, they are just gut packed full of the good stuff...and the good stuff doesn't smell too good. This should only been happening when your 1st cut them open.
That smell its a good smell, (as bad as it may smell) when you gut pack your feeders, their stomachs have partially digested food. All that food in their stomachs is what smells, if the fish tank itself smells bad than this is not the case. The reason store bought feeders dont smell bad is, petstores rarely keep feeder fish long enough to be worth feeding, hence the skinny feeders vs. your plump feeders, Nothing is wrong with them, they are just gut packed full of the good stuff...and the good stuff doesn't smell too good. This should only been happening when your 1st cut them open.