Trace Elements in Reef Tanks: What to Dose and What to Skip

Trace elements like iodine, strontium, potassium, and iron play roles in coral health but are controversial in the hobby.\n\nElements worth dosing (with testing):\n- Potassium: Important for coral coloration, target 380-420 ppm\n- Iodine: Benefits soft corals and shrimp molting, dose conservatively\n- Iron: Critical for macroalgae in refugiums\n\nElements replenished by water changes:\n- Strontium: Regular water changes maintain adequate levels\n- Boron: Rarely deficient with quality salt mix\n- Molybdenum: Trace amounts from salt mix sufficient\n\nICP-OES Testing:\n- Send water sample to lab for comprehensive analysis\n- Tests 30-40 elements at once\n- Costs $30-50 per test\n- Recommended quarterly or when troubleshooting\n- Popular labs: ATI, Triton, Fauna Marin\n\nGolden rule: Don't dose what you don't test. Excess trace elements can be as harmful as deficiencies. Regular 10-15% weekly water changes with quality salt mix replenish most trace elements naturally.