There are a number of ways to control phosphates in a reef tank. A protein skimmer and regular water changes will help to keep phosphates in check as will bio pellets. You can also use macro algae in an algae scrubber, algae reactor or refugium. Another alternative is Granular Ferric Oxide (GFO) in a media reactor. All of these options were discussed in a prior blog post.
But one option not discussed was the use of Lanthanum chloride. Lanthanum chloride works by binding and exporting phosphate in a reef tank. A number of companies have Lanthanum chloride based products that were designed specifically for use in aquariums. Tread Lightly – There are Risks You do have to be careful when using these products so it is very important to read the directions. The key is to not allow Lanthanum chloride to precipitate out into a display tank. A slow drip over time is essential. The product should be dripped into a very fine filter sock (5 – 10 microns). The filter sock acts as a mechanical filter to trap the fine precipitate. If these particles make their way into an aquarium then fish can perish, especially tangs. Fish essentially choke from the lack of oxygen since the substance impacts their gill plates.