Soft pellets are pliable and small fish can eat larger pellets when the pellets are soft compared to if the pellets were hard. I have never seen Purina Pond Chow. Does it really have 5 sizes of pellets? I do not use it because of its slow protein content.
A recent study found that bgill & HBG (4") grew best on Food with 42% protein (44% analysis)compared to 32%, 38%, 40% and 45% protein levels.