Last fall, the old liner ruptured, 21ft above ground, so before closing I put a new liner in, and filled it with clean local tap water. i didn’t add anything before closing and the water is still perfectly clear. currently we have a cartridge filter, but we want to go with a SWG setup, so I understand I will be getting a sand filter, pump, and SWG unit itself. I basically want to know what is recommended, I want the most economical option, but at the same time don’t want to buy a bad product. Amazon has intex sand filter with SWG for less than $500. I also need to know if I need to do anything special with the water, since it is at this point completely untreated.