feeder tank

Question
I have a pacman frog and I like to feed him feeder fish once in a while.  I found that the most echonomical large feeder is minoes from a bait shop (2.5"-3" long).  most feeder fish in pet stores are way too small and he doesnt even bother with them.  the problem I have is that the minoes just constantly die for no apparent reason. Every day I wake up and there's 2-5 dead.  I usually buy 1-2 dozzen and they go into a 10 gal tank that has a very large filter on it (filter for up to 60 gal).  I dont know if minoes just die for no reason naturally or if it's a temparature issue or if getting a 29 gal would make them live longer?  They're kind of pretty (shiney silver) so I wish I could keep them like a regular tank and just take one out once a week for the frog but that doesnt seem to work that way.
Any help would be much appriciated.

Answer
Hi Mark,
Im not sure if you have a heater or not but Minnows prefer a tank without a heater.
I also think you are overstocked as 24 minnows in a 10g tank is going to be very crowded.
Is the tank fully cycled? If not then thats why they are dying. Please tell me if you need help with cycling your tank.
Hope this helps!

Chloe