I'll bet the gnats are why you're seeing some seedlings fade away. I don't think peroxide and water is going to have much of an effect on them. I've used Gnatrol (an organic larvaecide), and it works great. The problem with Gnatrol is that it takes a while to find it in 'homeowner/gardener' quantities, and when you do, it's usually repackaged from an Ebay seller, and while all that's going on, you're still losing seedlings. Also, it doesn't seem like it has a very long shelf life, so you have to re-purchase it every year. When it was readily available as premix in pints and quarts, it was my go-to solution. Now, for here-and-there fungus gnat issues I just get some Bayer Insect and Disease control and be done with them. It contains both a systemic (Imidacloprid) and contact insecticide. Imidacloprid is the stuff that hurts bees, but since these seedlings aren't going to be flowering any time soon, I don't consider it a major problem. I think the fungus gnat issue probably wouldn't have become all that bad if the plants were outside, because the temps are cooler and they have a lot of competition outdoors.

Temperature-wise, a daylily seedling would shake low 30's off, no problem, but these are in pots, which have much lower protective thermal mass than the earth normally provides. They could be put outside now, even though they've been grown comparatively 'soft', but I'd leave them on the ground or a concrete pad, and cover them during rain and at night. On a table, they'll be losing heat from all sides. They'll probably lose some of their leaves, (more from the direct sun than the cold, I'd guess) but the new growth will be sturdy and after about three weeks they should bulk up and look better than they do now. There's a slim chance that some of them could go dormant from the change, but that shouldn't last very long. After a short winter rest, my potted dormants are showing signs of growth—many of them have ramets an inch above the soil already, which puts them two or three weeks ahead of their normal schedule.

@Seedfork Larry's posts earlier in this thread will give you an idea of what kind of conditions daylily seedlings will take.

My seedling seem to have done fine outdoors down into the teens with several nights in a row down into the twenties on two occasions. My cups are mostly planted in the ground, but I do have those 12 cups of seedlings sitting in a plastic ice cream tub, only one seedling so far appears to have died or gone dormant (will have to wait and see if it returns). I have many more mature daylilies that are planted in the ground and there are quite a few them that have gone completely dormant also ( I grow quite a few dormants) some dormants do well here while others do not, it is just trial and error ( that seems to be the case with any daylily).
I just finished a new bed, 10x10 feet. I laid out ten rows and plan to space my seedlings 1 foot apart in the rows. That is pretty wide spacing for seedlings but I have high hopes! The plan is to make about one or two more such beds (gradually emptying out all my cups) but those beds won't be completed until later in the year. I added compost and milorganite and high nitrogen fertilizer to the bed along with tons of leaves ( there is basically very little dirt to plant in) and by late March or early April I hope to start planting ( hoping to decompose a lot of the organic material I have added in that bed before planting time.)

My new flower bed should be done in a week or so. I have really debated on planting some of my seedlings now, just a couple to see how they do. I have some seeds in the frig that are ready to be planted now, they have been in there for 5 or 6 weeks now. I was planning on planting them directly into the new bed. I think I will move my seedlings outside today, and see what happens. Thanks for all the great advice.

New bed is done, seeds have been planted, covered them with plastic, since we have rain coming, don't want them to wash away. Next week I will start planting some seedlings.

I know you must be excited to finally get some seeds in the ground!
It is a shame the bed will miss a good rain, but I know you don't want to lose your seeds.

We are suppose to get 2 inches, and I am scared it will wash my seeds. I only cover the part where the seeds are, not the whole bed. I am gonna plant some seedlings this week also, and see how they do. I am so excited for this spring, to see if any of my new flowers bloom. When I had this bright idea to plant the seeds, we were not suppose to get scattered rain, maybe 1/2 after I got it all done, I got a weather alert about the 2 inches, and there was no way to find all those seeds I put in the ground lol. I am so excited to have those seeds in the ground, now to play the waiting game on seeing sprouts, I would say about 1/4 of them had already germinated, and had the little white nubs coming out the seeds.

Looking good.

Looks good, Catherine.

Larry, I only lost one or two of mine. I have really neglected them though. Some of the foliage died off when the cold blasted through. The tips were yellow on some but I've yet to feed them anything. I'm planning to pot them next weekend, something I've procrastinated now for months. I will start foliar feeding after they're potted with a 1/4 strength water soluble fertilizer.

Be careful not to leave that plastic on if it gets sunny and warm, Catherine. I don't know what your forecast is other than the rain you've mentioned, but hot sun on/through plastic can kill plants.

@sooby
I took the plastic off, after the rain the temperature varies highs 50-60 lows 34- 50 there will he one night it suppose to be 29 here.