Today, nearly every household has a smart toilet. But smart toilets often become clogged due to long-term accumulation of excessive scale. The cause is often not the toilet, but the water, which is not filtered. A filter angle valve is therefore needed, especially for use with smart toilets. It filters out all impurities so as to effectively prevent the toilet from clogging due to scale accumulation, and reduces the amount of water needed to flush. The angle valve’s handle has a built-in blue LED which indicates when the filter needs to be replaced.