We believe in giving your pool what it needs and not charging extra for it. There is one charge one time a year at the beginning of the season for 2 special chemicals which most companies don't use but makes for a better pool. One is a metal and mineral binder to protect the surface and the other is Phosphate remover which takes out organic material from the water, usual charge is a mere $30 once a year we simply pass along the cost of the two chemicals used. Pool filters are an essential part of a swimming pool.