It is possible to under-fertilize or overfertilize Peace Lilies.
Excess fertilizers will lead to salt build-up, toxifying the soil and inhibiting proper root growth.
Under fertilization may not be a common issue for most plant parents because Peace Lilies are light feeders, but it does occur.
Most plants need sunlight to grow, but a few prefer low light conditions.
Too Much Light:
Peace Lilies will also scorch quickly in direct sunlight.
Too Little Light:
The common symptoms of too little light are yellow or brown leaves, no flowers, small leaves, and very slow growth.