How cold is your temps? Anacharis will tolerate cooler temperatures and shade.

Hi, it's been in the upper 50's during the day, and last night it was 29. Last 2 weeks, it was upper 60's and night temps were in 40's. I picked up a floating thermometer so I can take the temp tomorrow.
Pond is in full sun and is 18" deep. Fish have been in for awhile now along with the lilly. Its also raining now and more rain expected.

water temp is 50 this morning. So should I put some type of fertilizer in the bucket of water that the anacharis is in and keep them in the house at night??

Just keep them in the bucket. You shouldn't need fertilizer right now. I think you won't need to keep them inside for more than two weeks, three at the most. Mine stayed outside, in a plastic barrel, all Winter and came back as soon as the temps started rising. Right now, there is Azolla growing on top of it and it might even bloom if I leave it in there like that.

It will be fine. I would not give it any Miracle Gro just plant it in the pond.

From experience.... NO FERTILIZER it may cause algae to grow in your pond. I received some weak looking hyacinths that I put in a bucket with Miracle Grow... they perked right up and I plopped them in my pond without washing the roots off.... well, that summer I had the worst case of algae ever

Thank you all for the advice! I ended up putting them in the pond and so far they are doing good.