Phytoplankton Dosing & Storage

Adding live marine phytoplankton to your reef aquarium is a natural way to support a healthier, more balanced ecosystem. As a nutrient-rich food source, phytoplankton benefits corals, clams, copepods, zooplankton, and other filter-feeding organisms by providing essential vitamins, minerals, and amino acids. It may also help support water quality by consuming excess nutrients such as nitrates, phosphates, and silicates, which can contribute to unwanted algae growth. When used as part of a regular feeding routine, live phytoplankton can encourage vibrant coral color, improved growth, and greater biodiversity throughout your aquarium. 

Recommended Starting Dosage 

Every aquarium is different, so it is best to start with a small amount and increase slowly based on how your tank responds. Monitor water clarity, nutrient levels, coral response, and overall aquarium health. 

How to Use Live Phytoplankton

Start with a small amount of live phytoplankton and adjust slowly based on how your aquarium responds. Every reef system is different, so it is best to begin conservatively and monitor your water clarity, nutrient levels, coral response, and overall tank health.

For most aquariums, small daily doses work well because they provide a steady food source for corals, clams, feather dusters, sponges, copepods, and other filter feeders. Daily dosing also helps maintain consistency in the system rather than adding a large amount all at once.

When dosing, add phytoplankton to an area of moderate to high flow, such as the display tank or return section of the sump, so it can circulate throughout the aquarium. Avoid overdosing, especially in newer or smaller systems. If the water becomes cloudy, nuisance algae increases, or cyanobacteria appears, reduce the dose or pause temporarily until the tank stabilizes.

Storage and Handling

Live phytoplankton is a perishable product and should be refrigerated as soon as it arrives. Keeping it cold helps slow activity and maintain freshness.

Shake the bottle gently but thoroughly before each use to evenly suspend the phytoplankton cells. It is also a good idea to shake the bottle every day or every couple of days, even when you are not dosing, to prevent settling at the bottom.

Store the bottle away from direct light and always keep it sealed when not in use. Before dosing, check the culture for freshness. Healthy live phytoplankton should have a clean ocean-like or fresh seaweed smell. Do not use it if it smells sour, rotten, or unusually foul, or if the bottle shows extreme separation, discoloration, or sludge-like buildup.

Good Signs to Watch For

When your aquarium is responding well to phytoplankton, you may notice improved polyp extension, more visible copepods at night, healthier filter feeders, and stable nutrient levels. Corals, clams, sponges, feather dusters, and other small organisms may show a stronger feeding response over time.

Signs You May Be Using Too Much

Reduce your dose if you notice persistent cloudy water, bacterial film, sudden cyanobacteria or nuisance algae growth, or unusual changes in nitrate and phosphate levels. A protein skimmer may also react more strongly after dosing, but if it continues for more than a day, consider lowering the amount used.

Q and A

- How often should I add live phytoplankton to my aquarium?
Most aquariums do well with consistent doses. Daily dosing is often preferred because it provides a steady food source for filter feeders and microfauna. Start low and adjust based on your tank’s response.

- Can I overdose phytoplankton?
Yes. Adding too much can lead to cloudy water, bacterial blooms, nuisance algae, or cyanobacteria. Start with a small amount and increase slowly only if your system is handling it well.

- Do I need phytoplankton if I do not have coral?
Yes, phytoplankton can still benefit your aquarium. It feeds copepods and other microfauna, supports biodiversity, and provides nutrition for filter feeders such as clams, feather dusters, and sponges.

- Can phytoplankton help feed copepods?
Yes. Phytoplankton is one of the primary foods for copepods. Regular dosing can help support a stronger pod population, which may also provide a natural food source for fish and corals.

- Where should I dose phytoplankton?
Add it to an area with good water movement, such as the display tank or return section of the sump. This helps distribute it throughout the system.

- How do I know if my phytoplankton is still good?
Fresh live phytoplankton should smell clean, like the ocean or fresh seaweed. If it smells sour, rotten, or foul, it should not be used. The color should also look fairly consistent after shaking.

- Does phytoplankton affect nitrate and phosphate?
Live phytoplankton may help consume nutrients such as nitrate and phosphate, but every aquarium is different. Monitor your levels regularly and adjust your dosing as needed.

• Do I need to refrigerate live phytoplankton?
   Yes. Always keep live phytoplankton refrigerated and shake before use to keep the cells suspended.

Questions or concerns? 

E-mail Alex@longislandtropical.com or text us at (516)-366-0245