The blockage in your tub filtration system should be removed in order to make sure the proper flow of water through it. The system might get blocked due to the presence of minerals in hard water and you will be able to remove it successfully by spraying filter cartridges using a hose every week. You should be very particular about using filter cleaner every month in order to thoroughly clean the filter and keep it in perfect operating condition. Don’t forget to keep the tub filter soaked overnight in a mixture of muriatic acid and water in 1: 3 proportions and it should be done twice a year.  Make sure to use protective goggles and gloves while treating the filter with muriatic acid. Additionally, replace it every 3 years to enjoy perfect filtration of water during soaking. 