Russell Hobbs Brita Filter Coffee Maker Getting Algae Inside

The water tank of the Russell Hobbs Brita filter coffee maker is getting algae inside, and it's really hard to clean it from the outside. No matter how many times I try using vinegar and baking soda to get rid of the algae, it keeps coming back in the tank the very next day. The water tank of the coffee maker smells musty, even if there is no water left inside. Instead of coffee, it makes a gross water that's all gross and yucky with algae and wetness. I've looked in the user manual and searched online, but I can't find a solution anywhere. I hope the brand can help me find a solution.