Haha, no they dont Fred, they dont eat fertilizer or manure either.
It is best to prepare a pool with fertilizer, but it needs doing the year before.
Dapnia will expode around 18 to 20 degrees, around the end of May (spawnng time)with naturally gives the fry the food they need.
Those fish will be fine, they look 2 or 3 years old, and feed a few pellets per week, or fit a fish feeder to the pool if its not in use, and start fertilizing in May.
My skimmers are now 10 years old, and i put 7000 in, and they are a pound and half now.
A carp would be that big as a 2 year old!