Can I get more soul fragments if I reach 3 hearts? (Sky Factory 2.5)

[doxiMAN_MAN]

I want every farm of mine to have 5 reinforced watering can, but I have reached 3 hearts and whenever I try to get more it give me a weak soul fragment... How can I fix that (If I even can)?

 

[sgbros1]

Get an unsuspecting friend or find a Soul of the Forgotten Deity (1/43 million chance by player killed mobs, 10x more likely with a kikoku)