---
product_id: 7019874
title: "Reef Phytoplankton, 250 mL / 8.5 fl. oz."
brand: "seachem"
price: "4127 kr"
currency: ISK
in_stock: true
reviews_count: 13
category: "Seachem"
url: https://www.desertcart.is/products/7019874-reef-phytoplankton-250-ml-8-5-fl-oz
store_origin: IS
region: Iceland
---

# Optimized for marine & freshwater tanks Concentrated 250 mL formula Proudly made in USA Reef Phytoplankton, 250 mL / 8.5 fl. oz.

**Brand:** seachem
**Price:** 4127 kr
**Availability:** ✅ In Stock

## Summary

> 🌿 Elevate your aquatic ecosystem with every drop — don’t let your tank miss out!

## Quick Answers

- **What is this?** Reef Phytoplankton, 250 mL / 8.5 fl. oz. by seachem
- **How much does it cost?** 4127 kr with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.is](https://www.desertcart.is/products/7019874-reef-phytoplankton-250-ml-8-5-fl-oz)

## Best For

- seachem enthusiasts

## Why This Product

- Trusted seachem brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Tank Health Booster:** Enhances invertebrate vitality and encourages natural behaviors like feather duster expansion within days.
- • **Easy & Precise Dosing:** Concentrated liquid formula ensures hassle-free, mess-free feeding with measurable results.
- • **Trusted US Manufacturing:** Crafted in the USA with rigorous quality control for consistent, reliable aquarium care.
- • **Scientifically Backed Nutrition:** Premium phytoplankton blend supports filter feeders and invertebrates with essential nutrients.
- • **Versatile Marine & Freshwater Use:** Engineered to nourish both saltwater corals and sensitive freshwater clams—no more feeding guesswork.

## Overview

Seachem Reef Phytoplankton is a concentrated 250 mL liquid supplement designed to provide essential nutrition to marine and freshwater filter feeders, including clams and corals. Manufactured in the USA, this scientifically formulated product supports invertebrate health and vitality, improving tank dynamics without clouding water. Ideal for mature, fully-cycled tanks, it requires careful dosing to avoid salt stress in freshwater species, making it the go-to choice for discerning aquarium managers seeking optimal aquatic balance.

## Description

Reef Phytoplankton, 250 mL / 8.5 fl. oz.

Review: Liquid Invertebrate Food - Seachem is a company that invests resources in thorough scientific research. Their products are some of the best in the industry and most are reasonably priced. This product was designed to add marine phytoplankton to your tank. Many invertebrates are filter feeders. I keep six freshwater clams (a Corbicula species) in my fish tank. These are filter feeders. They feed by filtering algae and microorganisms from the water. So no, dumping flakes in the water is not going to work. The problem is, every invertebrate food on the market was designed for marine use. Salt water. They are designed to feed corals, clams, and marine invertebrates. So it took a while to find a product that also works in the freshwater environment. A lot of the invertebrate foods on the market are live organisms suspended in water. They will not work for freshwater clams. Why? Because these marine organisms will die in freshwater. The Seachem is a concentrated product of preserved organisms. Phytoplankton, or algae if you prefer. In my very humble experience, this works better than the live products for a freshwater environment. The phytoplankton in the Seachem are dead but still hold their nutritional value. Okay look, if you're a clam you might prefer something alive and flavorful. But sometimes, even privileged clams living in the First World have to make do. There is just not a lot of option for feeding freshwater clams. So you freshwater clams out there better adjust your attitudes when it comes to food. Feeding at the recommended rates are not going to work for freshwater clams. You see, the feeding rates were calibrated for feeding marine clams. Marine clams get most of their nutrition from photosynthesis. So these liquid foods are supplemental. That is not the case with freshwater clams. They must get all of their nutrition from what they can filter from the water. And there is not going to be a lot of edible yummies in a freshwater tank. Most freshwater tanks are over-filtered and the water does not have enough green algae. You will have to feed daily. Do this carefully on a mature, fully-cycled fish tank, and you will not have an ammonia spike. Most freshwater clams start filtering when the lights come on. Give them some time to wake up and start filtering. Do not target feed. Do not dose the product close to the clams. This product has a very high salt content to preserve the algae and because it was designed for marine use. Pour your dose far enough away from the clams so that they do not get dosed with sodium chloride. Salt can easily kill your freshwater clams. Turn off your filter during feeding time. Your clams cannot compete with your filter. You do not want the filter to remove the phytoplankton before the clams can feed. There is just not a lot of information out there for freshwater clams. I want to share my experience. Feel free to skip if it gets boring. I have six freshwater clams in a 20 gallon tank. Six tetras and four Amano shrimp also share this glass condo. It is a moderately planted tank. I am very careful to avoid putting any kind of copper in this tank. Most plant fertilizers contain copper. A lot of fish foods contain copper. So let me warn you. Make sure the tank is fully-cycled and mature (at least a year old) before adding shrimp and clams. Also, make sure your fish are all very healthy. Reason? Because you will not be able to medicate this tank after you add the clams. The clams are very, very sensitive to anything you add to the water. Even ich medications that do not contain copper can kill them. If you get an ich attack in a tank with clams, you may have to make a choice. Save the fish and kill the clams or sacrifice the fish. Be warned. This ain't my first rodeo with clams, folks. I learned a lot and through many loses over the past five years. Clams will not tolerate medication. Do not use Fluorish Excel liquid carbon in any tank that has clams. Fluorish Excel is a very good source of C02 for plants and it also has the added benefit of killing algae in a fish tank. Which is fine in most planted tanks. But deadly for the clams. The chemical itself is dangerous to the clams. And the fact that it kills floating algae is bad because the clams feed on algae. The only plant fertilizer that I use in this tank is a product made by a company called Aguarium Co-op. It is their shrimp safe liquid fertilizer called "Easy Green". Dose at half the recommended rates. I removed the foam sponge from the Seachem Tidal 35 power filter. I am only using the bagged Matrix rocks in this filter. Even so, I turn the filter to its lowest setting during feeding time. I leave it in this lowest settig for about 4 hours after adding the Seachem Phytoplankton to allow the clams to feed. I dose one capful on top of the water. I let the product disperse. Do not worry. This product is concentrated. You do not need to make the water cloudy. I check to see if the clams are still feeding after two hours. If they are, I will add another capful. Wait a few more hours and then you can turn the filter back to its highest flow rate. I have had these clams for 2 months. I bought six and I still have six. Another food that works is Kent Marine's Microvert. Use the Kent as a supplement, but use the Seachem as the main entree. I have tried Two Little Fishies' Phytoplan. Phytoplan is a powder that you mix in water. It does not work as well for my purposes. The powder floats on top of the water. It is hard to saturate. Keeping freshwater clams in a fish tank has its challenges. You can make it easier by keeping an invertebrate only tank. In other words, no fish. The problem is, fish get sick and then you have to medicate. Clams will not tolerate medication. Do a google search on freshwater mussel die offs. These creatures are so sensitive that most biologists are not even sure what is killing them in our rivers. Keep chemicals out of your fish tank when you have clams. I want to say this product is highly recommended. It's not a perfect solution for freshwater clams. But it does work. The best method is to culture your own algae. But that is not easy to do. And who wants a fish tank with cloudy green water. Culturing is tricky. You do not want to foul the water in the tank. Because, you guessed it, clams are sensitive. They are a lot more sensitive than the cherry shrimps that most people keep. Use this Seachem because it is the best alternative out there. It is a very good product.
Review: 5 stars. Improved tank and helped feather dusters. - Bought this for my saltwater tank because I recently bought feather dusters. Feather dusters were not really coming out of tube and opening up that much. After a few days of receiving this item they have completely opened up and add a lot of character to tank. Good sized bottle for price paid. I follow instructions on back of bottle and has improved my tank. Works within a few days. Would buy again

## Features

- This product is easy to use
- This product adds a great Value
- This product is Manufactured in United States

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004YLJ822 |
| ASIN  | B004YLJ822 |
| Age Range Description | All Life Stages |
| Batteries | 1506 Lithium Metal batteries required. |
| Batteries  | 1506 Lithium Metal batteries required. |
| Best Sellers Rank | #29,826 in Pet Supplies ( See Top 100 in Pet Supplies ) #266 in Aquarium Water Treatments |
| Brand Name | Seachem |
| Color | natural |
| Customer Reviews | 4.5 4.5 out of 5 stars (1,008) |
| Date First Available | April 29, 2011 |
| Date First Available  | April 29, 2011 |
| Department | Unisex-Adult |
| Department  | Unisex-Adult |
| Directions | 1. Shake the bottle well before use. 2. Add the recommended dosage to the aquarium or pond, depending on the target species and specific uses for the product. 3. For best results, use in conjunction with Seachem's Reef Complete or Matrix. 4. Store in a cool, dark place. |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 1.94 x 1.94 x 6.5 inches |
| Item Package Dimensions L x W x H | 6.54 x 1.93 x 1.93 inches |
| Item Weight | 250 Grams |
| Item model number | 1506 |
| Item model number  | 1506 |
| Manufacturer | Seachem Laboratories, Inc. |
| Manufacturer  | Seachem Laboratories, Inc. |
| Manufacturer recommended age  | 1 month and up |
| Material | Plastic |
| Model Name | 1506 |
| Number of Items | 1 |
| Product Dimensions  | 1.94 x 1.94 x 6.5 inches; 8.82 ounces |
| Size | 250 ml/ 8.5 fl. oz. |
| Specific Uses for Product | Behavior |
| Target Audience Keyword | algae-eaters, betta-fish, bottom-feeder-fish, cichlid-fish, fish, goldfish, invertebrate-fish, mollusks, octopuses, rays, sharks, snails |
| Warranty Description | Warranty |

## Product Details

- **Brand:** Seachem
- **Item Form:** Liquid
- **Item Weight:** 250 Grams
- **Liquid Volume:** 250 Milliliters
- **Manufacturer:** Seachem Laboratories, Inc.

## Images

![Reef Phytoplankton, 250 mL / 8.5 fl. oz. - Image 1](https://m.media-amazon.com/images/I/71ywIIhCYgL.jpg)

## Questions & Answers

**Q: can i use this to feed baby brine shrimp?**
A: Yes you can. You want to make sure you have some water flow so it circulates properly in the tank.

**Q: Can it be used as a nitrogen-enhanced fertilizer for plants?**
A: Sounds like a good experiment.  I do not know

**Q: Mine smells like vinegar and is a brown color, is this good?**
A: Yes. It's dead phyto. Not green like live phyto.

**Q: Can I feed Sucker fish with this?**
A: No it is meant for corals and filter feeders

## Customer Reviews

### ⭐⭐⭐⭐⭐ Liquid Invertebrate Food
*by C***I on August 27, 2020*

Seachem is a company that invests resources in thorough scientific research. Their products are some of the best in the industry and most are reasonably priced. This product was designed to add marine phytoplankton to your tank. Many invertebrates are filter feeders. I keep six freshwater clams (a Corbicula species) in my fish tank. These are filter feeders. They feed by filtering algae and microorganisms from the water. So no, dumping flakes in the water is not going to work. The problem is, every invertebrate food on the market was designed for marine use. Salt water. They are designed to feed corals, clams, and marine invertebrates. So it took a while to find a product that also works in the freshwater environment. A lot of the invertebrate foods on the market are live organisms suspended in water. They will not work for freshwater clams. Why? Because these marine organisms will die in freshwater. The Seachem is a concentrated product of preserved organisms. Phytoplankton, or algae if you prefer. In my very humble experience, this works better than the live products for a freshwater environment. The phytoplankton in the Seachem are dead but still hold their nutritional value. Okay look, if you're a clam you might prefer something alive and flavorful. But sometimes, even privileged clams living in the First World have to make do. There is just not a lot of option for feeding freshwater clams. So you freshwater clams out there better adjust your attitudes when it comes to food. Feeding at the recommended rates are not going to work for freshwater clams. You see, the feeding rates were calibrated for feeding marine clams. Marine clams get most of their nutrition from photosynthesis. So these liquid foods are supplemental. That is not the case with freshwater clams. They must get all of their nutrition from what they can filter from the water. And there is not going to be a lot of edible yummies in a freshwater tank. Most freshwater tanks are over-filtered and the water does not have enough green algae. You will have to feed daily. Do this carefully on a mature, fully-cycled fish tank, and you will not have an ammonia spike. Most freshwater clams start filtering when the lights come on. Give them some time to wake up and start filtering. Do not target feed. Do not dose the product close to the clams. This product has a very high salt content to preserve the algae and because it was designed for marine use. Pour your dose far enough away from the clams so that they do not get dosed with sodium chloride. Salt can easily kill your freshwater clams. Turn off your filter during feeding time. Your clams cannot compete with your filter. You do not want the filter to remove the phytoplankton before the clams can feed. There is just not a lot of information out there for freshwater clams. I want to share my experience. Feel free to skip if it gets boring. I have six freshwater clams in a 20 gallon tank. Six tetras and four Amano shrimp also share this glass condo. It is a moderately planted tank. I am very careful to avoid putting any kind of copper in this tank. Most plant fertilizers contain copper. A lot of fish foods contain copper. So let me warn you. Make sure the tank is fully-cycled and mature (at least a year old) before adding shrimp and clams. Also, make sure your fish are all very healthy. Reason? Because you will not be able to medicate this tank after you add the clams. The clams are very, very sensitive to anything you add to the water. Even ich medications that do not contain copper can kill them. If you get an ich attack in a tank with clams, you may have to make a choice. Save the fish and kill the clams or sacrifice the fish. Be warned. This ain't my first rodeo with clams, folks. I learned a lot and through many loses over the past five years. Clams will not tolerate medication. Do not use Fluorish Excel liquid carbon in any tank that has clams. Fluorish Excel is a very good source of C02 for plants and it also has the added benefit of killing algae in a fish tank. Which is fine in most planted tanks. But deadly for the clams. The chemical itself is dangerous to the clams. And the fact that it kills floating algae is bad because the clams feed on algae. The only plant fertilizer that I use in this tank is a product made by a company called Aguarium Co-op. It is their shrimp safe liquid fertilizer called "Easy Green". Dose at half the recommended rates. I removed the foam sponge from the Seachem Tidal 35 power filter. I am only using the bagged Matrix rocks in this filter. Even so, I turn the filter to its lowest setting during feeding time. I leave it in this lowest settig for about 4 hours after adding the Seachem Phytoplankton to allow the clams to feed. I dose one capful on top of the water. I let the product disperse. Do not worry. This product is concentrated. You do not need to make the water cloudy. I check to see if the clams are still feeding after two hours. If they are, I will add another capful. Wait a few more hours and then you can turn the filter back to its highest flow rate. I have had these clams for 2 months. I bought six and I still have six. Another food that works is Kent Marine's Microvert. Use the Kent as a supplement, but use the Seachem as the main entree. I have tried Two Little Fishies' Phytoplan. Phytoplan is a powder that you mix in water. It does not work as well for my purposes. The powder floats on top of the water. It is hard to saturate. Keeping freshwater clams in a fish tank has its challenges. You can make it easier by keeping an invertebrate only tank. In other words, no fish. The problem is, fish get sick and then you have to medicate. Clams will not tolerate medication. Do a google search on freshwater mussel die offs. These creatures are so sensitive that most biologists are not even sure what is killing them in our rivers. Keep chemicals out of your fish tank when you have clams. I want to say this product is highly recommended. It's not a perfect solution for freshwater clams. But it does work. The best method is to culture your own algae. But that is not easy to do. And who wants a fish tank with cloudy green water. Culturing is tricky. You do not want to foul the water in the tank. Because, you guessed it, clams are sensitive. They are a lot more sensitive than the cherry shrimps that most people keep. Use this Seachem because it is the best alternative out there. It is a very good product.

### ⭐⭐⭐⭐⭐ 5 stars. Improved tank and helped feather dusters.
*by C***P on July 20, 2025*

Bought this for my saltwater tank because I recently bought feather dusters. Feather dusters were not really coming out of tube and opening up that much. After a few days of receiving this item they have completely opened up and add a lot of character to tank. Good sized bottle for price paid. I follow instructions on back of bottle and has improved my tank. Works within a few days. Would buy again

### ⭐⭐⭐⭐⭐ Awesome product
*by B***L on June 23, 2025*

Why did you pick this product vs others?: Good product

## Frequently Bought Together

- Reef Phytoplankton, 250 mL / 8.5 fl. oz.
- Seachem Reef Zooplankton 250 ml.
- Seachem Reef Plus 500ml

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*Product available on Desertcart Iceland*
*Store origin: IS*
*Last updated: 2026-01-23*