First Aquaplants

So this is my first aquatic plant experiment. I found this beautiful plant as plant of the month at my local Maidenhead aquatics. It’s beautiful and I couldn’t resist. Sadly I don’t have much equipment, so I went with what I had and tried for a Walstad method of setup. So here is what I have

House plant soil
Pond gravel
Alter anthers Cardinalis
Floating Hornwart

Water started off a little cloudy but the water cleared up beautiful and quite fast. It has its own grow lamp and is in a fairly well lit spot.

My questions. Is this looking ok? What’s the white stuff on the leaves? I can see some small snail looking things, there is a few in there, they are tiny and hard to photograph but move very fast.. any idea? I was thinking of doing a half water change soon, good idea? What can I do to help it?

I was hoping to give it 6 or so weeks and see how it’s going and then maybe add some cherry shrimp?

Thanks