How much water do you take out of a ten gallon tank when cleaning?

Typically, when cleaning a ten-gallon tank, you should remove approximately 25-30% of the water. This is because when cleaning the tank, you are also stirring up debris and waste that has settled at the bottom. Removing a portion of the water helps to ensure that these wastes are removed effectively. Additionally, removing too much water can cause stress to the fish and disrupt the tank's ecosystem. Therefore, it's recommended to remove a moderate amount of water for cleaning purposes.