---
product_id: 4156359
title: "Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml"
brand: "seachem"
price: "€ 10.72"
currency: EUR
in_stock: true
reviews_count: 12
category: "Seachem"
url: https://www.desertcart.ie/products/4156359-seachem-flourish-excel-bioavailable-carbon-organic-carbon-source-for-aquatic
store_origin: IE
region: Ireland
---

# Bioavailable organic carbon source Precise dosing for optimal plant growth Iron-reducing for better nutrient uptake Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml

**Brand:** seachem
**Price:** € 10.72
**Availability:** ✅ In Stock

## Summary

> 🌱 Unlock your aquarium’s green potential—grow smarter, not harder!

## Quick Answers

- **What is this?** Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml by seachem
- **How much does it cost?** € 10.72 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ie](https://www.desertcart.ie/products/4156359-seachem-flourish-excel-bioavailable-carbon-organic-carbon-source-for-aquatic)

## 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

- • **Enhance Iron Absorption:** Promotes ferrous iron (Fe+2) availability, ensuring your plants get the nutrients they crave for vibrant health.
- • **Simplify Photosynthesis:** Bypasses natural carbon chain steps with ready-to-use compounds, accelerating plant metabolism and growth.
- • **Algae Control Powerhouse:** Effectively combats stubborn algae like black beard algae, keeping your tank pristine and Instagram-worthy.
- • **Boost Plant Growth Effortlessly:** Delivers bioavailable organic carbon that fuels lush aquatic plants without complex CO2 systems.
- • **Flexible, Low-Maintenance Dosing:** Use daily or every other day with easy capful measurements tailored to your tank size—perfect for busy plant parents.

## Overview

Seachem Flourish Excel is a 250 ml organic carbon supplement designed to boost aquatic plant growth by providing bioavailable carbon and enhancing iron uptake. It simplifies photosynthesis by supplying ready-made carbon compounds, supports algae control, and offers flexible dosing for low-tech planted tanks. Trusted by aquarists for over 20 years, it’s ideal for maintaining vibrant, healthy aquatic plants without the complexity of CO2 injection systems.

## Description

Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml

Review: Good for growing healthy plants - In combination with either Flourite or Eco-complete substrates, I've used Excel for years for my planted tanks. With zero buffering capacity (kh) in the pH 8 well water I had, using a CO2 system guaranteed gorgeous plants but dead fish because of the resulting the wide swings of pH. Excel allows me to have a low tech tank and works wonders for the low to medium light plants that I prefer (crypts, anubias, java ferns, along with higher light wisteria and egeria densa used to combat algae from getting established before the plants do). I now have pH7 water with 2 degrees of hardness and will continue with Excel. For my latest tank (20 long), I've been adding 2ml every day -- it took a month for the plants to establish and start growing. I'll taper off to every other day soon. I expected the crypts to completely melt when first planted because, well, they are crypts and that's what they do. But they didn't melt and are already putting out new leaves and coloring up nicely. This tank also has 2 small desertcart swords planted in the higher light areas of the tank -- they lost their original leaves (they were grown emerged) and now have beautiful truly submerged foliage. I don't have any luck using liquid fertilizers or laterite - I'm amazed at all the different kinds of algae I managed to grow when I used them. By using Excel and adding Osmocote pelleted fertilizer deep under the substrate just where heavy feeding plants' roots are, that seems to limit excess nutrients. I've heard that egeria densa doesn't do well with Excel but mine is doing great and growing like a weed while floating over the top of the water. It's never affected my fish, snails or shrimp either.
Review: AMAZING for algae - This stuff is awesome. My tank had the hard to remove "black beards algae." Scraping, cleaning, sponges, razor blades.... nothing would remove it. Got a recommendation to try this. 2 capfuls and 4 days later and the algae is almost gone, a week later and it's like it was never there. Easiest solution to the most annoying problem ever. The bottle should last awhile as you dont need much to get results. Worth every penny.

## Features

- CARBON PRODUCTION: All plants require a source of carbon, and Flourish Excel is a great and convenient source of bioavailable organic carbon.
- IRON PRODUCTION: Flourish Excel also possesses iron reducing properties, thus promoting the ferrous state of iron (Fe+2), which is more easily utilized by plants than ferric iron (Fe+3).
- PHOTOSYNTHESIS: Plants must produce longer chain carbon compounds (photosynthetic intermediates). By dosing with Flourish Excel you bypass the involvement of chain carbon compounds, and introduce the already finished, structurally similar compounds.
- TREATMENT: On initial use or after a major (> 40%) water change, use 1 capful of Flourish Excel (5 mL) for every 40 L (10 US gallons). Thereafter, use 1 capful for every 200 L (50 US gallons) daily or every other day. For smaller dosing please note that each cap thread is approximately 1 mL.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001EUE6SC |
| ASIN  | B001EUE6SC |
| Age Range Description | all |
| Best Sellers Rank | #29,674 in Pet Supplies ( See Top 100 in Pet Supplies ) #277 in Aquarium Water Treatments |
| Brand Name | Seachem |
| Color | clear |
| Country of Origin | United States |
| Customer Reviews | 4.6 4.6 out of 5 stars (2,333) |
| Date First Available | June 15, 2004 |
| Date First Available  | June 15, 2004 |
| Department | Unisex-Adult |
| Department  | Unisex-Adult |
| Directions | See Packaging |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 4.9 x 2.4 x 2.2 inches |
| Item Package Dimensions L x W x H | 6.57 x 1.81 x 1.77 inches |
| Item Weight | 1.06 ounces |
| Item model number | 456 |
| Item model number  | 456 |
| Manufacturer | Seachem Laboratories, Inc. |
| Manufacturer  | Seachem Laboratories, Inc. |
| Manufacturer recommended age  | 1 month and up |
| Material | Plastic |
| Model Name | Seachem Flourish Excel Bioavailable Carbon |
| Number of Items | 1 |
| Product Dimensions  | 4.9 x 2.4 x 2.2 inches; 1.06 ounces |
| Size | 250 ml |
| Specific Uses for Product | Indoor |
| Target Audience Keyword | fish, unisex-adult |
| Warranty Description | Warranty |

## Product Details

- **Brand:** Seachem
- **Item Form:** Liquid
- **Liquid Volume:** 250 Milliliters
- **Manufacturer:** Seachem Laboratories, Inc.
- **UPC:** 780231504224 000116045605

## Images

![Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml - Image 1](https://m.media-amazon.com/images/I/510f5gSD3nL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Good for growing healthy plants
*by A***R on October 18, 2015*

In combination with either Flourite or Eco-complete substrates, I've used Excel for years for my planted tanks. With zero buffering capacity (kh) in the pH 8 well water I had, using a CO2 system guaranteed gorgeous plants but dead fish because of the resulting the wide swings of pH. Excel allows me to have a low tech tank and works wonders for the low to medium light plants that I prefer (crypts, anubias, java ferns, along with higher light wisteria and egeria densa used to combat algae from getting established before the plants do). I now have pH7 water with 2 degrees of hardness and will continue with Excel. For my latest tank (20 long), I've been adding 2ml every day -- it took a month for the plants to establish and start growing. I'll taper off to every other day soon. I expected the crypts to completely melt when first planted because, well, they are crypts and that's what they do. But they didn't melt and are already putting out new leaves and coloring up nicely. This tank also has 2 small Amazon swords planted in the higher light areas of the tank -- they lost their original leaves (they were grown emerged) and now have beautiful truly submerged foliage. I don't have any luck using liquid fertilizers or laterite - I'm amazed at all the different kinds of algae I managed to grow when I used them. By using Excel and adding Osmocote pelleted fertilizer deep under the substrate just where heavy feeding plants' roots are, that seems to limit excess nutrients. I've heard that egeria densa doesn't do well with Excel but mine is doing great and growing like a weed while floating over the top of the water. It's never affected my fish, snails or shrimp either.

### ⭐⭐⭐⭐⭐ AMAZING for algae
*by A***K on March 24, 2025*

This stuff is awesome. My tank had the hard to remove "black beards algae." Scraping, cleaning, sponges, razor blades.... nothing would remove it. Got a recommendation to try this. 2 capfuls and 4 days later and the algae is almost gone, a week later and it's like it was never there. Easiest solution to the most annoying problem ever. The bottle should last awhile as you dont need much to get results. Worth every penny.

### ⭐⭐⭐⭐⭐ Seachem Flourish Excl
*by D***E on July 31, 2014*

I haven't used this long, but I have enjoyed the results so far. I have several plants in a 2-gallon Betta tank. I dose the tank with Flourish, Flourish Iron, and this. And I have seen growth within the first week. I have to dose in very small amounts (1 drop is less than half the recommended dose for that size, two drops is too much) but I do see a difference. I have avoided Excel for the longest time because I heard the stories of people overdosing (accidentally or not) and killing everything in their tank. I can dose correctly, but I didn't want to take the risk with something so dangerous to tank life even if slightly overdosed. I am currently cycling the tank that the plants are in, so no fish yet, but I am sure it will be safe even at the recommended dose, let alone half it. I see lots of people saying they "prefer Excel to Flourish." They are completely different products. Flourish is a micro trace element fertilizer. Excel is a carbon-providing fertilizer. They can be used in conjunction, or separately, but they are separate products. They should not be compared "one or the other." The active ingredient is actually a sterilizer, and is used in some algaecide products. So this means yes, it can be used to kill algae. However Seachem does not market it as such, so you will find no official approval of the product as such from them. The bottle, unlike other Seachem product bottles, contains a ratcheting child safety cap. I see some people say it breaks easily on them, but I haven't had mine break yet. This has a cap like that for a very good reason. This stuff could be dangerous. Not only can some people react to it if it touches their skin or they breath it, but it should be kept well away from anyone who might think it would be a good idea to pour it in a tank, because "it's a fertilizer, so it'll be good for the plants." All fertilizer products should be kept up, but if you overdose with Flourish, you are likely only to have an algae problem if you don't do a water change soon enough. If you overdose with Excel, it will kill everything in the tank.

## Frequently Bought Together

- Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml
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*Product available on Desertcart Ireland*
*Store origin: IE*
*Last updated: 2026-03-08*