A clean pool cannot be determined by a physical examination alone. A pool with clean water that looks good doesn't mean the water is clean. There are many contaminants that are not visible – including ammonia, nitrates, bacteria, etc. Therefore, regardless of the filter solution, there must be a chemical component to complement the mechanical filter element. Ideally, the chemical components break down the toxins in the water and make them harmless.
Biological filtration is one of the most important types of filtration for the Eco-ponds. It works chemically and uses biological bacteria to break down the ammonia waste that the fish excrete in the pond. You can get a biofilter in two ways – permanent and disposable.
Image Source: Google
If you have a choice, go for the permanent one. The reason is, the bacteria that accumulate in the filter media are beneficial. If you use a disposable filter, you will be removing good bacteria every time you remove the filter. A better way is to use a permanent filter, rinse it, and replace it – while holding most of the good bacteria in place.
An organic water purifier or pool filter is a special type of filter, the work of which is based solely on natural materials. A good example is a special combination of rock, carbon, and silicates. As water flows through this combination of ingredients, they absorb minerals from the water, helping to keep it clean and pure.
A perfect example of an organic filter solution is filling your pond with slugs. Snails act as part-time garbage collectors. Slugs love algae if you grow a lot of algae in your pond. Of course, snails can help control it. Snails also overheat and rot fish food, which reduces the pollution of the lake.