I would not re-pot it if it's ailing now, you might end up losing the whole thing. Give it some time to adjust to it's new surroundings & light and it should start to grow new leaves with the right care.In the meantime if you have any leaves that are yellowing, or just look awful, you can pull them off, stem and all. Place it where it will receive bright indirect light. "Dapple" sun is ok. (No direct burning sun) Water the soil thoroughly when the top couple inches or so feel almost or close to dry, but not quite yet dried out.If the soil dries too much, the leaves will wilt and you can get brown tips, same with over-watering. I make sure mine gets watered BEFORE it wilts, because you could damage roots doing it that way. You don't want to water if it still feels wet after a weeks time (it shouldn't be) with the good draining. Ck back in a day or so if you don't think it's quit ready for a drink yet. Peace lilies like semi moist soil, not wet and not dried out. I would not fertilize your peace lily now. Ailing plants will not respond to it and it could make things worse. Wait until the plant is doing well and putting out new growth first. When you do use fertilizer, use half, or less strength and only now and then. If you see any leaves with some dried brown tips, that can be no big deal if it's being watered correctly. Using hard-water can cause brown tips, as well and over-feeding and over-watering and that can hold true for other plants as well. You can use rainwater, or distilled if brown tips bother you. Billy Rae

If most of the roots died, you should cut those rotting ones away to prevent spread. Then once you see what kind of healthy roots you're working with, you can decide an appropriate size pot. Even plants on the brink of death at the hands of humans will still try to live, so signs of new growth could mean one of two things: a) you've fixed your over watering problem and the plant is getting better Or b) the overwatering problem has gotten worse and the plant is desperately trying to stay alive despite our best efforts to kill it. Lol.

Try using a "tell" to tell you when it's time to water: 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

PLs usually produce from offsets that grow from the roots of the mother plant. They can be grown from seed, but it's fairly uncommon to do so, so the former method has garnered much more favor. At this point, it's important to avoid saturated soil anywhere in the pot. Do the following outdoors or while holding the pot over a sink: Move the pot downward, then reverse the direction sharply upward. Excess water in the pot will tend to continue moving downward when the direction is reversed, and out of the drain hole. The sharper the change in movement from down to up, the more water will exit the pot. Before or after this exercise, you can trim all the leaves off about an inch above the point where the individual leaf stems can be clearly seen. It would be a good idea to make/use a 'tell' to keep you apprised of moisture levels deep in the pot. If your pot is deeper than about 5", the advice to "water when the top inch or two of soil feels dry to the touch, is a recipe for over-watering; and this would be most true when the plant in question has no foliage. Keep the pot in a warm bright spot. It's quite common for the tops of some plants to collapse either as a drought response (too dry) or from over-watering (too wet). If you don't see the plant pushing new growth within a few weeks (a month or so), it's a good bet it isn't going to make it. You'll find no credible information suggesting fertilizer should be withheld from stressed plants. It's a horticultural myth. A plant's systems are designed to work in concert with a full compliment of nutrients in the grow medium at all times. If a plant needs supplemental nutrition - it needs supplemental nutrition, whether it's stressed or not. Al