Marine Reef Supplements: Which Additives Does Your Tank Need?
By Pro Shrimp | Published: 2026-10-20
Category: Buying Guides
Choosing the right reef additives can be confusing. This guide explains the key roles of trace elements, vitamins, and alkalinity buffers, and gives clear decision rules for your tank.
Quick answer
Most reef tanks need at least a trace element replenisher and an alkalinity buffer. For corals showing slow growth or pale color, add a vitamin and amino acid supplement like Seachem Reef Plus. Match your additive to your tank’s bioload and coral type.
Trace elements vs. vitamins vs. alkalinity
A reef tank consumes trace elements (strontium, iodine, iron) as corals and invertebrates grow. If you only do water changes, these elements slowly drop below optimal levels. A dedicated trace supplement like Seachem Reef Trace restores them without adding nitrate or phosphate.
Vitamins and amino acids are not always critical, but they can boost coral coloration and tissue growth in systems with heavy lighting or high coral density. Seachem Reef Plus provides a broad spectrum of these compounds. It is safe to use alongside trace supplements.
Alkalinity (KH) is the most frequently depleted parameter in a reef tank because corals use carbonate to build skeletons. A concentrated buffer like Seachem Reef Carbonate raises KH quickly. Do not confuse it with a trace element product.
When to add extras
If your tank has soft corals and low fish load, a weekly trace supplement and regular water changes may be enough. For SPS-dominated systems or tanks with high growth rates, you will likely need daily dosing of both alkalinity buffer and trace elements.
Seachem Reef Pack Enhancers bundle calcium, strontium, and iodide in one package. This is convenient if you already manage alkalinity separately but want to target calcium and strontium without measuring each element individually.
Decision rules for choosing reef additives
- Start with trace elements: If you have never dosed additives before, begin with a trace element supplement like Seachem Reef Trace. Dose weekly according to the label for tanks with moderate coral load, or twice weekly for SPS-heavy systems. If your tank is new or has only fish, skip additives until corals are added.
- Add vitamins when corals need a boost: If you notice pale tissue, sluggish growth, or poor polyp extension after two weeks of trace dosing, add Seachem Reef Plus. Use it once per week. It can be combined with Reef Trace in the same dosing session. Do not use vitamins daily; overuse can cause bacterial blooms.
- Manage alkalinity separately: Test KH at least twice a week. If it drops below 8 dKH, use Seachem Reef Carbonate to raise it. Dose in small increments (1 mL per 20 gallons) and retest after 30 minutes. Never mix alkalinity buffer with calcium or trace supplements in the same container—precipitate will form.
Product facts
- Seachem Reef Plus: Seachem Reef Plus contains a broad spectrum of vitamins, trace minerals, amino acids and fatty acids vital to fish and coral health. Use this when corals appear stressed, pale, or growth has slowed—it provides nutrients that water changes alone may not replenish.
- Seachem Reef Trace: Seachem Reef Trace supplies a broad range of trace elements and is nitrate/phosphate free. This is your baseline additive for any reef tank; it restores consumed elements without fueling algae blooms.
Who should use this approach
Best for
- Reef keepers with mixed coral tanks (soft, LPS, SPS) who want a simple step-by-step dosing routine
- Aquarists who already test KH and want to add trace elements without risking algae problems
Not ideal for
- Tanks that rely solely on frequent water changes (30% weekly) to replenish elements—extra additives may not be needed
- Ultra-low-nutrient systems where even trace elements can cause nutrient spikes if overdosed
