How to Remove Silicates Naturally from Saltwater

Silicates in seawater and aquarium water can cause problems in the balance of of the aquarium system. Specifically, high levels of silicates in seawater can result in a diatom bloom (also called brown algae). There are several ways of removing silicates from the water and several ways to prevent them from entering the aquarium system.

Things You'll Need

  • Reverse osmosis/deionizing filter
  • Ferric iron oxide
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Instructions

    • 1

      Use only reverse osmosis and deionized water or distilled water. Reverse osmosis forces water through a very fine mesh to remove nearly all contaminates; however, silicates can get through the filter but will be removed by using deionizing resin. You can purchase a reverse osmosis/deionizing filter online and at some specialty aquarium stores.

    • 2

      Use only argonite sand in the aquarium. Play sand from the hardware store is usually make from silicates and the silicate sand will leach into the water.

    • 3

      Let the diatoms grow. Diatoms will take up the silicates from the water, and you can let them flourish and remove them by siphoning them off rocks and glass. This will remove the silicates from the water. If you have a sump (separate filtration system) set up with your aquarium, you can let the diatoms flourish in the sump and out of sight of the main aquarium.

    • 4

      Use ferric iron oxide in the filtration system. This will remove both silicates and phosphates, key chemicals needed by algae to thrive. Ferric iron oxide is sold under several brand names for use in aquariums. Frequent changes of the substance is necessary to prevent the silica from leaching back into the water.