Check the listing for details. Tropic Marin Pro-Coral A- 200mL Trace 1 Liquid Essential Anionic Trace Elements. Condition: New. Listed at 17.99 USD. Tropic Marin Pro-Coral A- 200mL Trace 1 Essential Anionic Trace Element Supplement for Reef Aquariums Dose with Pro-Coral K- Trace 2 For the best results! In the ocean, there are tiny amounts of essential trace elements such as iodine, lithium, manganese, etc. that can be depleted rapidly in household aquariums as corals and invertebrates grow. Tropic Marin Pro-Coral A- and Pro-Coral K+ are formulated to replenish those elements in an easy to dose balanced, liquid additive. When trace element levels start to get low corals can lose their color and stop growing completely. Doser ReadyEasy to useNo mixing required to useContains required anionic trace elementsSupports natural coral color and growth Instructions: For a complete trace elements supply, we recommend the use of both trace element solutions, Pro-Coral A- and Pro-Coral K+. Add 1 ml trace elements of each solution per 100 l / 25 US-Gal. of aquarium system water volume daily. The trace elements solution must not get directly onto the animals. The demand for trace elements increases with increased aquarium population density. In heavily populated aquariums, dosage may be increased up to the maximum dosage below. Maximum dosage: Do not exceed a dosage of 2 ml per 100 l / 25 gallons of aquarium system water volume per day. Pro-Coral A- Trace 1 Contains: BromineFluorineIodineLithiumMolybdenumSeleniumVanadium