When you water, do you water thoroughly until it runs out the bottom, then allow to drain thoroughly? If it’s in a cache pot, dies it sit in drained water?

Yes water runs out the bottom for about 30 seconds and then stops. The pot is a terracota pot with one large drainage hole on the bottom so I don' think the water is sitting in the pot. There are also rocks in the bottom two inches of the pot to help with drainage.

If the soil is moist and still you have willted leaves, then its root rot. Stop watering, let soil dry out

Peace Lily: Basic Care (spathiphyllum) https://youtu.be/_8GcYVdAPy4

Qiuck care guide

The plant will wilt from over-watering or under-watering. If the plant wilts when the pot feels light and you can detect no moisture in the grow medium, it's under-watered. If it wilts when you can easily detect moisture in the pot, you're very likely over-watering; and if not, the plant's root system is probably severely compromised.

If you allow the grow medium to become too dry, it becomes hydrophobic (water-repellent) and difficult to remoisten. You can fix this by watering before a "tell" tells you the plant is completely dry. In the event the medium does become too dry, the tendency is for the medium to shrink away from the walls of the pot, providing an unobstructed pathway by which the water can run across the top of the soil and into the void between the soil and the pot walls w/o having restored any significant measure of moisture to the medium.

You should also have an appropriate nutritional supplementation program in place, as you cannot depend on the medium to provide the building blocks (nutrients) the plant needs to grow normally.

Using a 'tell'

Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant.

Watering in small sips leads to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor.

In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water.

Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'.

One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue.

Al

I prefer multiple drainage holes, but with the one hole you just need to be a bit more careful. I like to raise the pot to drain it, or tilt it. Also, in future, do not add rocks to the bottom. Search tapla’s posts for perched water table :)

also bear in mind you did disturb the roots when repotting, and may take some recovery time.

A link to what Hibiscus referred to.

This might also prove helpful.

Al

In my experience once the soil is dry and the plant has started to wilt- you have waited to long to water it. For my peace lilies when it is warm I water them when the 1st inch of soil is dry. I take mine inside for the winter under growth lights and the temps stay between 55 to 64 degrees. When they are inside in the colder basement I let the soil dry out 2 inches before watering.