Elos Expert Line is our range of professional high grade saltwater marine additives designed to prevent mineral and organic depletion in an aquarium. With modern filtration systems that we use in our aquariums, it has become more important to consider each of the key elements normally in NSW (Natural Sea Water). In order to keep stable and proper water conditions. ExpertLine additives are designed and formulated to provide the advanced aquarist the tools to individually maintain each of the key aquarium water parameters. Unlike most additives, ExpertLine additives are highly concentrated, packed in brown glass bottles and blended to give medium and long term results rather than simply increasing levels in the short term. Typical ELOS ExpertLine additives come in a 25ml bottle, and will treat approximately 12,500 litres/3300 US gallons. ELOS ExpertLine additives should be used by experienced aquarists only. If you prefer the same quality ingredients in an easier/less critical form, consider the ELOS PrimaLine Additives.