No, it won't be. Unless you aren't taking the chlorine out. You must always use a dechlorinator. If you are taking the chlorine out etc, then it'll be because he's so starved and malnourished his immune system is not good.
Honestly, I'd stop feeding bloodworms all together. If he's hungry enough he will eat any of the above. Blanche your worms - if you don't they can taste sour and that puts some axolotls off (mine don't care). It makes them get rid of all the sludge inside of them (poo if you like). Now he's not in the fridge he will have a larger appetite than when he was in the fridge. Just keep trying.
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