well i purchased a spectra pure ro/di unit from my cousin and wanted to go ahead and order the new filters for it cus god only know how long its been since they have been changed. long story short Mary Ann at AquaFX was so helpful, she wasn't afraid to answer any question i had, and her employee's were actually getting mad cus they wanted to leave but still stayed on the phone with me. so if anybody needs new filters or just have a question in reference to ro/di units call them before you call anybody else. no idea if there prices are cheaper or not but there customer service is grade A.