You saved an aquarium scene to Photos, set it as your lock screen, and nothing moves. Or the moving version was there yesterday and today it is a flat picture.
Live wallpaper on iPhone has changed shape several times, so plenty of the instructions online describe a version of iOS that no longer exists. What animates, and when, depends on which iOS you are running, which kind of wallpaper you picked, and whether the file still has its motion attached.
Here is how to find which of those it is, in the order worth checking.
First, three different things get called "live wallpaper"
Most of the confusion starts here, because the three behave nothing alike.
The first is a Live Photo: a still frame with a second or two of video attached, captured by the camera or produced by an app. Through iOS 15 you could set one as a lock screen wallpaper and play it by pressing and holding the screen. The lock screen was rebuilt in iOS 16 and that option did not come across with it. Apple has moved this ground more than once, so the honest instruction is to open the wallpaper gallery on your own phone and see what it offers.
The second is Apple's own moving wallpapers. Astronomy zooms toward Earth when you wake the phone, Weather follows current conditions, Photo Shuffle changes the picture on a schedule. These move at particular moments rather than continuously.
The third is the parallax shift, the slight movement of the image as you tilt the phone. That one is governed by Reduce Motion, in Settings > Accessibility > Motion.
If you expected the first and got the third, nothing is broken — the phone is doing what your iOS version supports.
Check these five, in order
Work down the list. Each one rules out a whole category.
Your iOS version. Open the wallpaper gallery and see whether a moving option is offered at all for the type you picked. If it is not there, no setting will bring it back.
Reduce Motion. Settings > Accessibility > Motion. This suppresses the tilt effect, and people often turn it on for other reasons and forget.
Low Power Mode. It reduces some motion and visual effects while it is active.
The always-on display. On the Pro models from iPhone 14 onward, the idle lock screen is dimmed and static, so anything that plays on wake will not play there. Tap the screen and watch again.
The file itself. In Photos, open the image and look for the Live badge in the corner; tap it to confirm it says Live rather than Off. If the badge has gone, the video half was lost somewhere along the way — and that is the most common cause of all.
Save straight from the app to Photos
The motion in a Live Photo lives in a second file paired with the still, and most ways of moving a picture around break that pairing. Sending it to yourself in a chat app, uploading and downloading it again, or running it through an editor that does not understand Live Photos all produce a flat image. Save from the wallpaper app straight into your library and set it from there, with no detour.
Why the home screen never animates
This one is not a fault. The home screen has never played moving wallpaper on iPhone, on any version. It is a surface you scroll, with icons, folders and widgets layered on top, and constant animation behind that would compete with icon labels and draw power for as long as the screen is on.
What you get instead is a choice. In the editor, tap Customise, open the Home Screen panel, and pick Blur, a plain colour, a gradient, or a different photo. Blur is usually most useful, because it keeps the colour of your lock screen image and removes the detail that fights with app names.
Nothing on the lock screen loops, either
Worth setting expectations, because it is the second most common disappointment. No iPhone lock screen animates continuously in the background, and that is deliberate. Motion happens at moments: when you wake the phone, unlock it, tilt it, or when a shuffling wallpaper is due to change.
So a scene that plays for a second or two on wake and then holds still is working correctly. If you were picturing a fish tank running all day, that is not a setting you have missed.
No app can set your wallpaper for you
One more thing that gets read as a bug. iOS gives third-party apps no way to change your wallpaper directly. Every wallpaper app therefore works in two steps: it saves the image or Live Photo into your Photos library, and you set it yourself. Aquarium 3D: Live Wallpapers works that way too, so the flow is preview the scene, save it, then set it from Photos or Settings.
If you need the setting steps themselves rather than the diagnosis, How to Set a Live Wallpaper on Your iPhone walks through the whole flow.
Quick answers
Can I set a video file as my wallpaper?
Not directly. iOS accepts photos and Live Photos, not video files. Apps offering video wallpapers convert the clip into a Live Photo first, which is why the result depends on whether your iOS version plays Live Photo wallpapers at all.
Why does my wallpaper look zoomed in?
iOS crops the image to fill the screen, so anything smaller than your display gets scaled up. Start from an image at least as large as your screen resolution and reposition it by pinching. The tilt effect also crops slightly at the edges, since it needs room to move.
The motion worked and then stopped. What changed?
Check whether the phone updated iOS, whether Low Power Mode came on, or whether you re-saved the picture through another app. Any of the three can turn a moving wallpaper into a still one without warning you.
Does an animated wallpaper hurt battery life?
Only a little, because it is a still image most of the time and only moves at specific moments. Screen brightness and screen-on time cost far more. A dark wallpaper on an OLED iPhone does help, since unlit pixels draw no power.
Where to get it
If you want the scenes without the file-handling problems, Aquarium 3D: Live Wallpapers previews each aquarium in a phone-shaped frame and saves straight into your Photos library, so what you set is what you looked at.
Set one, then check it once in daylight and once in a dark room before deciding you like it.