Choosing the Best Phytoplankton for Your Reef Tank: Live, Pure, and Powerful

Phytoplankton is a key part of maintaining a balanced reef tank, providing essential nutrients for filter feeders, corals, and other marine organisms. But not all phytoplankton products are created equal. At Reef Solutions, we offer a unique blend of live, untreated phytoplankton that stands out from other options on the market. Recently, a customer asked about the difference in color between our phytoplankton and a competitor’s, sparking a great discussion on the importance of quality in phytoplankton products. Here’s a breakdown of our conversation.

Customer Question:
“Just curious about the color difference between what I have and what I bought from you. Your bottle is a light green color, while mine is darker to almost black. Should I add more phytoplankton from your bottle since it's lighter, or is that just the color because it’s new?”

Reef Solutions’ Answer:
At Reef Solutions, we use a blend of green phytoplankton, specifically Nannochloropsis and Tetraselmis Phytoplankton. We avoid browns, reds, or golden phyto strains, so you’ll see a bright green color in our bottles. Here are some other details that make our phytoplankton product unique:

• Truly Live Phytoplankton – Our "Live Phyto" phytoplankton is completely alive, untreated, and free of additives. Some competitors’ phytoplankton products may appear darker because they’ve included multiple strains or possibly treated their product to prevent cell division, which can extend shelf life but may reduce vitality.
• Cell Concentration – The color difference can also come down to cell size and concentration. In our product, smaller (2-5 microns per cell) strains like Nannochloropsis need a higher cell count per milliliter due to their size before the solution becomes opaque.  Also the nature of each individual strain have specific colours.  Nannochloropsis for instance, is often a bright to medium green while Tetraselmis leans ever so slightly towards a darker green.  Based on our tools of estimation, our phytoplankton contains roughly 10,000,000 cells PER ML.
• Dosing Advice – For most tanks, we recommend a dose of 5–25ml per 100 gallons. Each tank is unique, so feel free to start with 5ml and adjust as needed based on your tank’s response.

When comparing our product to others, you might notice they sometimes mix multiple strains, including brown phyto, giving a darker look. And though some brands offer “live” phytoplankton, they may have treated it with UV or other methods to prevent cell growth and division. If you’re unsure, check the expiration date, as this can also affect color and potency.

Ultimately, live, pure, untreated phytoplankton supports a healthier tank ecosystem by delivering the full nutrient profile nature intended.

For some quick videos on our Live Phyto densities, check out our Facebook page.