Ich treatment and live plants?

Dan M, as usual, has no idea what he is talking about. He cut and pasted his answer from a inaccurate web site. The guy is a hack, who has no idea how to properly keep fish. Let alone plants. Please don't listen to the fool. He has a small penis complex. He feels he needs to improperly advise people on tropical fish, due to his small penis. Such a shame. It would be nice to see him answer a question with some experience of his own, rather than plagiarizing others, and linking hack web sites.

To answer your question, your plants will be fine.

Hornwort does not handle heat, or medications, well. It is actually a kind of freshwater macroalgae and not really a vascular (true) plant. Sometimes muskgrass is accidentally sold as hornwort. They are very similar and when grown in the aquarium, the simplest way to tell them apart no longer applies. Muskgrass when grown outdoors in a sunny pond develops a smell when crushed that repels most plant eating fish.

Whichever one you have, Chara spp. or Ceratophyllum demersum, is likely to be affected. If you can move it out of the aquarium into a container that gets light, it will grow and if there are no fish, any ich parasites in the water transferred over with the plants will die within a few days without any fish host.

I'm not sure a vase in a window is the best place for the hornwort. i was thinking more of something like a clear plastic sweater box. The sun's direct rays can over heat the water so a small desk lamp and a place away from the sun could be useful for this temporary set up.

You need 86F+ to kill ich.

You are raising it too slow. You are giving ich time to adapt. Their offspring produced in 82F will be more likely to adapt to 86F than the offspring produced in 76F. Their life cycle is short so every generation will be more adaptable to the new environment.

Raise 1~2F per hour is fine.