Red nymphea lilypads died

[Pezzep]

My red nymphae lilypads recently died off, there was three of them that looked good for a while then they randomly started melting off. Do they normally do this or do I not have enough nutrients in my water? I'm thinking of getting the dry ferts to make the pps-pro solution, but the only place I've found online to get all the supplies is about 48 dollars for a pound of each including shipping and handling, is this a good price?
By everything I mean
K2SO4 Potassium sulfate
KNO3 Potassium nitrate
KH2PO4 Monopotassium phosphate
MgSO4 Magnesium sulfate

 

[Fresh2o]

I could be wrong, but I believe lilies in generally heavy root feeders so liquid ferts may not help in this case.

 

[Pezzep]

Hmm, maybe my root tabs got used up. I recently put new ones in so hopefully that will help get new lilypads.