What It Is

Planktura F/2 Phyto Fertilizer Set is a two-part Guillard F/2–style nutrient system designed for culturing marine phytoplankton (microalgae) in home or commercial grow-out. It includes a Macro + Vitamins bottle (Part 1) and a Trace-Metal Complex bottle (Part 2) to keep the recipe balanced while protecting vitamin potency.

Why Reef Keepers Use It

If you want dependable, repeatable phytoplankton cultures for feeding copepods, rotifers, and reef filter-feeders, your culture media matters as much as your light and aeration. This is biology, not a chemical remover. You’re supplying the building blocks that let microalgae convert dissolved nutrients into harvestable biomass.

Core Benefits

Two-part system helps preserve vitamins by keeping them separate from trace metals until dosing.
Balanced macro (N and P) plus trace metals to support consistent growth across many common marine culture strains.
Designed for stable, repeatable results when your inputs are consistent (cleanliness, light, aeration, temperature).
Fully soluble concentrates for simple scaling from small bottles to larger culture vessels.
Clear 1:1 dosing makes it easy to standardize batches and reduce “mystery variables.”

How It Works

Macronutrients (nitrate and phosphate) supply core nitrogen and phosphorus for cell division and biomass production.
Vitamins (B1, B12, biotin) support key metabolic pathways that can improve culture consistency when inoculant health varies.
Trace metals (including iron and manganese) support photosynthetic machinery and enzyme function, while EDTA helps keep metals available in solution.
Culture density and timing depend on system conditions, not just fertilizer (light intensity and photoperiod, aeration and CO₂ availability, starting cell count, and contamination control).

How To Use

Shake both bottles well.
Dose 1:1 into your culture water:
- Standard: 1 mL Macro + 1 mL Trace per gallon (3.8 L)
- Metric: 0.25 mL Macro + 0.25 mL Trace per liter
Add Macro first, then add an equal volume of Trace.
Add your phytoplankton inoculant, then provide consistent lighting and gentle aeration.
Start low and adjust based on culture response if you’re changing species, light levels, or culture density targets.

Use Notes

Intended for phytoplankton culture vessels. It is not designed to be dosed directly into a display reef aquarium.
High-performance cultures come from repeatability: clean equipment, stable temperature, consistent light, and reliable airflow.
Storage: keep tightly sealed and protected from light. Refrigeration at 2–8 °C is recommended. Avoid heat (≥50 °C). Do not freeze.
Safety: not for human or animal consumption. Wear gloves and eye protection. Avoid ingestion, inhalation, and contact with skin or eyes. Keep out of reach of children and pets.

Ingredients / What’s Inside

Included:

1 × F/2 Macro | Part 1 (Macronutrients + Vitamins)
1 × F/2 Trace | Part 2 (Trace-Metal Complex)

Macro (Part 1): Purified water, sodium nitrate, monosodium phosphate, thiamine HCl (B1), vitamin B12, biotin.
Trace (Part 2): Purified water, ferric chloride, EDTA, cobalt chloride, zinc sulfate, copper sulfate, manganese chloride, sodium molybdate.

Learn More

If you want to split the kit, you can also purchase each part separately.

Need live phyto to feed the tank or to keep a culture line going? These Coral Shots options pair naturally with an F/2 culture workflow.

FAQ

Is this safe to dose into my reef tank to “feed” the tank?

It’s designed to feed phytoplankton in a separate culture vessel. Adding fertilizer directly to a reef tank can increase available nutrients and trace metals in ways that are hard to control.

Why is it split into two bottles?

Separating vitamins from the trace-metal complex helps preserve vitamin potency and improves shelf stability, especially once the product is opened and handled over time.

Will it guarantee a specific culture density or harvest timeline?

No. Culture outcomes depend heavily on light, aeration, inoculant quality, temperature, and contamination control. The fertilizer provides the nutrition, but the system determines the result.

Can I scale the dose for larger vessels?

Yes. Keep the 1:1 ratio and dose based on total culture volume. For best repeatability, measure accurately and keep your process consistent batch to batch.

Bundles

F/2 Phyto Fertilizer Set

Nutrient Restore Bundle

Hydroshock 3-Part Complete System