Hi I own the exact same tank! A few tips for you:
1. You can raise the water level even further, mine is full nearly to the top. Your newts won't need a dry area, just somewhere they can sit and lift their heads out the water. More water = a more stable environment.
2.I know you might've bought the tank due to the convenience of a built in filter, but that power filter is unsuitable for this species. It creates too much current which will stress the newts if constantly on. I do switch mine on about once a week for a whole day as part of my general cleaning, as it really keeps the water clear, but otherwise I have just a small sponge filter which I added to the tank. Don't worry the built in filter will still be there if you ever use the tank for something else.
3. Some of your gravel seems a bit small, make sure none of the pieces are smaller than the newts head. I use river rocks about the same size as the newts.
4. Add more plants! This species LOVES heavily planted tanks. Add some plants that grow all the way to the water surface for them to perch on, such as sprites and cabomba. cover the bottom with java moss, add more of the plants you already have. More plants=better water=healthier animals.