Growing your own phytoplankton has been on the list for a while. Not because the idea is complicated, but because turning the idea into a working culture requires having the right things in the right place at the same time, and the gap between researching what you need and actually ordering it tends to stay open longer than it should.
The decision to grow your own is usually driven by one of two things. The first is volume, a copepod refugium, a rotifer programme, or a heavily stocked reef tank consumes phytoplankton faster than occasional bought-in bottles conveniently supply, and the economics of producing it yourself start to make obvious sense. The second is consistency, a culture running in the corner of the fish room means phytoplankton is always available, always fresh, always at the density you need, regardless of delivery schedules or stock levels.
The Reefphyto Phytoplankton Culture Kit with Nannochloropsis gaditana gives you the complete starting point for both. It contains a 250ml live Nannochloropsis gaditana starter culture at approximately 2 billion cells per millilitre, 100ml of Guillard's f/2 nutrient formula, a 4-litre clear culture container, a 20ml dosing syringe, and an airline suction cup, available with or without an air pump. Add light, add prepared saltwater, follow the included step-by-step guide, and a productive culture ready for first harvest is typically established within 7 to 10 days. Same kit as the oculata version, with Nannochloropsis gaditana as the culture species for keepers who prefer to grow the species they are already familiar with from the ready-to-dose range.
Ten days after the kit arrives, the culture is producing. The copepod refugium has a reliable phytoplankton feed. The reef tank gets dosed daily from a vessel that refills itself within days of each harvest. The cost per litre of live phytoplankton falls to a fraction of bought-in pricing and stays there. This is the point at which growing your own stops being a plan and starts being a normal part of how the system runs.
Reefphyto has been culturing Nannochloropsis gaditana in Wales since 2008. The starter culture in this kit comes from the same production stock as the retail gaditana product. If you have questions once the kit arrives about setup, lighting, or getting the culture to harvest density, contact us directly. Darren responds personally.
Start the culture. End the dependency on bought-in phytoplankton.
The Point at Which Growing Your Own Makes Sense
There is a threshold in most reef keepers' live food journey where buying phytoplankton in finished form stops making practical sense. It is not the same threshold for everyone. it depends on tank size, the complexity of the live food programme, and how consistently phytoplankton is being dosed but most keepers who use phytoplankton regularly reach it eventually.
The signs are familiar. Ordering more frequently than feels efficient. Rationing doses when a bottle is running low and the next order has not arrived. The copepod culture running thin between deliveries because the phytoplankton supply is intermittent rather than continuous. A reef tank that gets dosed when a fresh bottle is on hand and goes without when it is not.
A home culture solves all of these at once. It is not a complicated operation. It is a vessel, a light, a nutrient solution, and a starter culture that divides and grows until there is more phytoplankton than the system needs, harvested regularly and replaced within days. The kit makes the first step as simple as it can be.
What the Kit Contains
The Nannochloropsis gaditana Phytoplankton Culture Kit contains everything needed to establish a productive home phytoplankton culture from a standing start.
The 250ml live Nannochloropsis gaditana starter culture comes directly from Reefphyto's own production stock at approximately 2 billion cells per millilitre. Nannochloropsis gaditana is a close relative of Nannochloropsis oculata and shares its key characteristics: cells measuring 2 to 5 microns, high EPA content, tolerance of a wide range of culture conditions, and fast doubling time under good light and nutrition. It is the species used in the retail Nannochloropsis gaditana product, which means keepers who are already dosing that product into their tank are growing the same culture species they have been buying.
The 100ml Guillard's f/2 nutrient formula is the same professional-grade nutrient used in Reefphyto's own production facility. It provides the nitrogen, phosphorus, trace elements, and vitamins that Nannochloropsis requires to produce dense, nutritionally complete cells at harvest. Cultures run on correctly formulated f/2 consistently outperform those run on improvised or incomplete nutrient solutions in both growth rate and cell quality.
The 4-litre clear culture container allows continuous visual monitoring of culture health without opening or disturbing the vessel. Colour is the primary indicator of culture status: pale green suggests the culture needs more light or nutrient, deep opaque green indicates it is at or approaching harvest density. The 4-litre volume is calibrated for a first home culture that produces enough to sustain a copepod refugium and dose a reef tank daily without requiring significant space or infrastructure.
The 20ml dosing syringe allows accurate, contamination-free nutrient addition and culture sampling. The airline suction cup holds the airline securely against the container wall. The optional air pump, available with UK plug, airline tubing, and adjustable air valve, provides the continuous aeration the culture requires.
Nannochloropsis Gaditana Versus Nannochloropsis Oculata for Home Culture
Both the gaditana and oculata culture kits use closely related Nannochloropsis species with similar cell sizes, EPA profiles, culture requirements, and feeding applications. The choice between them comes down to personal preference and familiarity rather than a significant performance difference in a home culture setting.
Keepers who are already using the Nannochloropsis gaditana retail product in their reef tank and want to grow the same species they are familiar with will naturally reach for this kit. Keepers who have been using oculata-based products, or who have no prior preference, may choose either. Both produce excellent results when the culture is set up and maintained correctly.
What matters more than the species choice is the quality of the starter culture, the nutrient formulation, and the consistency of light and aeration, all of which are addressed by the kit regardless of which version you choose.
Setting Up and Running the Culture
Sterilise the culture container before use with a dilute bleach solution, rinse thoroughly, and fill with 3.5 litres of prepared saltwater at 25 to 35 parts per thousand salinity. Add f/2 nutrient at the rate specified in the included guide. Add the 250ml starter culture. Set up aeration with the airline reaching the base of the vessel and the suction cup holding it in position. Place under your light source running 12 to 16 hours per day.
The culture will be visibly greening up within three to seven days. By days seven to ten under good conditions it will have reached first harvest density, a dense, opaque green that indicates a cell count sufficient for productive use. Remove 50 to 70 percent of the culture volume, replace with fresh saltwater and f/2 nutrient, and the harvested volume will be restored within three to five days.
The harvested phytoplankton goes directly into the reef tank, the copepod or rotifer culture vessel, or a brine shrimp enrichment container. The culture vessel sits under its light, aerating continuously, rebuilding towards the next harvest. This cycle, once established, runs indefinitely from a single starting point.
What a Running Culture Provides
A single 4-litre Nannochloropsis gaditana culture maintained on a regular semi-continuous harvest cycle typically produces two to three litres of dense phytoplankton per week under good lighting and consistent f/2 nutrition. This is sufficient to provide daily phytoplankton input to a reef tank of several hundred litres, feed a copepod refugium continuously, and sustain a rotifer culture alongside tank dosing in most home setups.
The per-litre cost of home-produced phytoplankton, once the initial kit investment is recovered, is a fraction of the equivalent volume purchased ready-to-use. For keepers with significant ongoing phytoplankton requirements the saving across a year of consistent culture operation is substantial.
Frequently Asked Questions
Is there a meaningful difference between this kit and the oculata version?
Both kits contain the same equipment and the same nutrient formula. The difference is the starter species. Nannochloropsis gaditana and Nannochloropsis oculata are closely related, share similar culture requirements, and perform comparably in reef feeding and live culture applications. The choice is largely one of personal preference or familiarity with one species over the other.
Do I need prior experience to set up this kit?
No. The included step-by-step guide covers the full setup process and addresses the most common early-stage questions around lighting, nutrient dosing, and culture monitoring. Nannochloropsis is the most forgiving species for home culture and tolerates the normal variability of a home environment well.
What lighting do I need?
A daylight-spectrum LED or fluorescent lamp positioned 10 to 20 centimetres from the culture vessel running 12 to 16 hours per day is sufficient for a 4-litre culture. A desk lamp with a daylight bulb works well. The closer the light to the culture surface the faster the growth rate, up to the point where the culture becomes dense enough to self-shade.
Can I scale up production from this kit?
Yes. Once the initial culture is established and producing consistently, additional vessels can be inoculated from the producing culture without purchasing a new starter. Each additional vessel multiplies production volume proportionally.
What if the culture crashes?
The most common causes of culture crashes are contamination, nutrient depletion, insufficient light, and temperature shock. The included guide covers how to identify and prevent each. If a crash occurs, the standalone Nannochloropsis gaditana product is available to restart without replacing the full kit.
Reefphyto - Live Phytoplankton Production in Wales Since 2008
Reefphyto has been culturing Nannochloropsis gaditana at professional scale in Wales since 2008. The starter culture in this kit comes from the same production stock we use every day in our own facility. If you have questions about setup, culture management, or integrating home phytoplankton production into your live food programme, contact us directly. Darren responds personally to every enquiry.
