Hi @Linda8,
Greetings from the Roku Community!
We're glad to assist you with your problem with the HD aquarium that is not working. What Roku device are you using right now? (e.g., Roku Express, Roku Streambar, Roku TV—specify TV) Please try to restart your Roku device from Settings > System > Power > System restart (if you do not see a Power submenu, skip to the next step).
Let us know how it goes, and we'll be glad to assist you further.
Kind regards,
Eunice
Eunice L.
Roku Community Moderator