Your peace lily looks to be in rather good shape for being "dumped" The only thing I would do is maybe pinch off any leaves that don't look all that healthy, maybe some that are yellowing (can't see them all from photo) or have holes, or rips

If it were mine, I'd keep it in the same pot for now, it looks to be the right size for the plant. If you decide to keep it after all and want a different looking pot, either use another one that's the same size pot that it's in now, or one that's just an inch around larger and only if the roots are badly root-bound.
Most plants, including the peace lily's like to be on the root-bound side anyway.
The brown water is probably just from the soil, but with the right watering, it should run pretty clear after a while.

Put it where it will get bright indirect light, no direct sun, or the leaves will burn. Water it thoroughly when the top inch of soil is getting close to dry, not dry as a bone dried out though. You want the soil to be semi most at all times, not wet and never dried out completely. I water mine almost always, once a week which is in a 10" pot during the warmer month, a little less in winter.

The brown leaf tips could be from under or over-watering, maybe too much fertilizer. I think I would just water it for now and in the spring & summer months, give it very diluted amounts when you water.

Good luck with your orphan!
Billy Rae

Aw, dumpster plant thanks you for your compliment and advice! He looks a bit better than he did at initial rescue, but still pretty scruffy. (He also has narrower leaves than I'm used to on a peace lily, but I'm assuming that's unrelated to his life story.)
The brown tips are certainly not from over-watering, at least not while I've had the plant. =P Should I stick him in the bathtub and pour gallons of water through the pot to try to flush out the brown and any possible residual fertilizer? Or just continue to water normally and look hopeful?
I'm also not sure how much of the plant I should remove at once. Brown leaves, duh; yellow leaves with brown, bye-bye; yellow leaves with green, should probably go; green leaves with yellow... that's where I start hesitating. Green leaf with one brown spot? Leaves that look green but have lost their "gloss"? I feel like I will end up removing about 60% of the plant, and I'm not sure if that would be good or bad.
Should I nip this bud (ha, ha)? It's currently sticking out pretty horizontally as a result of the Big Droop. The stalk has firmed back up, but I'm not convinced it will actually make a flower, nor that the plant should be bothering with flowers right now.

If there is a lot of leaves with brown/yellow tips, I'd just let them be, eventually those leaves will be replaced with healthier leaves later on.
Any yellowing leaves should go (not yellow/brown tips but yellowing leaves) just the real bad, or unsightly ones, torn leaves torn, dried up ones and leave the rest on for now so it's still a full plant if possible, a least until spring when new growth will start.
I'd just water it normally, the brown in the water will eventually work itself out with each watering.
The flower stem can be lifted vertically with a thin stake, or a thin stick lightly tied near the top of the stake to keep it upright.
Maybe the poor orphan was trying to send out a white flag so someone like you would see it and rescue it:>)

Good luck!
Billy Rae

I think it definately needs repotting with new soil but now is not the time. It is under stress so no need to cause more. They like to be kept moist but not wet and definately not in standing water. I wouldn't give it any food either. I would trim off the ugly and half dead as they are just using energy that needs to be diverted elsewhere. The brown water could be from rot but yet it looks to be in fairly good shape so I doubt that. Probably just bad soil. I would let it recover for a few months and see how it does and then repot. Depending on your house temps and your climate you could repot in March.

Good Luck and thanks for the rescue!

Thanks guys. For now I'll just circle the wagons and wait for spring. (As far as standing water, I hope there isn't much - it's one of those attached-saucer pots, but the water seems to drain pretty quickly through the slit, and previous-owner was kind enough to dump it along with a clear plastic tray to catch the runoff.)