Which filter do I need? Hot tubs have used a variety of filters. We try to show pictures and include size of filters for your information. When filters are best OEM rather than aftermarket we only offer the OEM. When the OEM and a specific filter manufacture's filter are exactly the same, we offer either both or the lower discounted one
What does it mean to "clean" the filter"? On a regular basis the filter must be cleaned. Spraying with a hose might visually clean the filter but the paper gets coated with oil and matter and it needs to be chemically cleaned. If you do not do this regularly, it can affect the heating and even cause pumps to fail. Regular depends on which unit you have. If you have a model with a standard size circulation pump, you should clean the filters at least monthly. If you have a small circulation pump, you should clean at least every 2 weeks if not weekly, depending on usage.
How do I clean it? As mentioned, spraying with water will not strip the off the paper. For the most part, bleach will also fail in emulsifying the oil. You need to deal with it with chemistry. First choice is buying a "filter cleaner" from a hot tub dealer. These are good products. Second and less costly is buying trisodiumphosphate or TSP. It's a powder you mix in hot water and soak the filters in for a couple hours and then rinse with a hose. You should find it in the painting or cleaning department at your hardware store. Lastly and I have customers who swear by it, powder dishwasher cleaner. Some customers put the filter in the dishwasher, turn off the dry cycle (or you get melted plastic) and let the dishwasher and cleaner do the work. I have seen the results and they look good. But no one in the industry will recommend that.