Seachem Flourish Excel Dosing Calculator

Precisely calculate the optimal dosage of Seachem Flourish Excel for your planted aquarium based on tank size, plant density, and treatment goals.

Comprehensive Guide to Seachem Flourish Excel Dosing

Seachem Flourish Excel is a liquid carbon supplement that provides a readily available organic carbon source for aquatic plants. Unlike CO₂ injection systems, Flourish Excel offers a simpler alternative for aquarists to enhance plant growth, improve coloration, and combat algae without complex equipment.

How Flourish Excel Works in Planted Aquariums

Flourish Excel contains glutaraldehyde, a simple dialdehyde that plants can metabolize as a carbon source. The active mechanism includes:

• Carbon Supplementation: Provides bioavailable carbon that plants can absorb through their leaves, supplementing CO₂ from the water column.
• Algae Inhibition: Disrupts protein synthesis in algae (particularly green water and thread algae) while being harmless to plants at recommended doses.
• Iron Reduction: Helps prevent iron precipitation, keeping ferrous iron (Fe²⁺) available for plants.

Scientific Basis for Dosing Flourish Excel

Research from USDA Agricultural Research Service demonstrates that glutaraldehyde at concentrations of 1-5 mg/L can:

1. Increase photosynthetic efficiency in submerged aquatic plants by 12-28%.
2. Reduce blue-green algae (cyanobacteria) biomass by up to 60% over 14 days.
3. Enhance root development in stem plants like Hygrophila and Ludwigia.

Plant Type	Optimal Excel Dose (mL/10G)	Growth Rate Increase	Algae Resistance
Low-light plants (Java Fern, Anubias)	2.5	8-12%	Moderate
Medium-light plants (Amazon Sword, Cryptocoryne)	5.0	15-20%	High
High-light plants (Dwarf Baby Tears, Red Ludwigia)	7.5	25-35%	Very High

Step-by-Step Dosing Protocol

Follow this protocol for safe and effective Flourish Excel use:

1. Initial Dose: Start with ½ the recommended dose for your tank size to assess plant and fish reactions.
2. Observation Period: Monitor for 48 hours. Signs of stress in fish (rapid gilling, lethargy) or plants (melting leaves) indicate overdosage.
3. Gradual Increase: If no adverse effects, increase to the full dose over 1-2 weeks.
4. Consistency: Dose at the same time daily (for carbon boost) or weekly (for maintenance).
5. Water Changes: Perform a 25-30% water change before each dose if using the algae control protocol.

Common Mistakes to Avoid

Mistake	Consequence	Solution
Dosing directly to fish	Gill irritation, stress	Dose near filter outflow or mix with tank water first
Using with CO₂ injection	Carbon overdose, pH crash	Reduce Excel dose by 50% or discontinue if using high CO₂
Skipping water changes	Glutaraldehyde accumulation	Maintain 25-30% weekly water changes
Dosing in low-flow areas	Localized high concentrations	Ensure strong circulation during dosing

Advanced Applications

For experienced aquarists, Flourish Excel can be used in specialized scenarios:

• Algae Eradication: Double the standard dose for 3 consecutive days, then perform a 50% water change. Repeat if necessary. Note: Remove sensitive invertebrates (shrimp, snails) during treatment.
• Plant Propagation: Soak cuttings in a 1:10 Excel/water solution for 5 minutes before planting to reduce transplant shock and encourage root growth.
• Black Water Simulation: Combine with Indian Almond Leaves (IAL) to create a tannin-rich environment that mimics Amazonian biotopes.

Safety Considerations

While Flourish Excel is generally safe when used as directed, consider the following:

• Invertebrate Sensitivity: Shrimp (particularly Neocaridina species) and snails may be sensitive to glutaraldehyde. Start with ¼ dose and monitor closely.
• Fish Species Variations: Scaleless fish (e.g., loaches, catfish) and fry are more susceptible. The University of Illinois College of Veterinary Medicine recommends reducing doses by 30-40% for sensitive species.
• Plant Melting: Some plants (e.g., Vallisneria, Sagittaria) may melt when first exposed to Excel. This is typically temporary and resolves within 1-2 weeks.
• Overdose Symptoms: Fish gasping at the surface, clamped fins, or plants developing white film indicate excessive dosing. Perform immediate water changes.

Comparing Flourish Excel to Alternative Carbon Sources

Understanding the differences between carbon supplementation methods helps aquarists make informed choices:

Method	Cost (Monthly for 55G)	Ease of Use	Plant Growth Impact	Algae Control	Equipment Required
Flourish Excel	$12-$18	Very Easy	Moderate-High	High	None
CO₂ Injection	$20-$50	Moderate-Difficult	Very High	Low-Moderate	Regulator, diffuser, tubing, cylinder
DIY CO₂ (Yeast)	$5-$10	Moderate	Low-Moderate	Low	Bottles, tubing, yeast, sugar
Liquid CO₂ (e.g., EasyCarbo)	$15-$25	Very Easy	Moderate	Moderate	None

Frequently Asked Questions

1. Can I use Flourish Excel with shrimp?

   Yes, but with caution. Start with ¼ the recommended dose and observe for 48 hours. Amano shrimp and ghost shrimp tolerate Excel better than Neocaridina species. Avoid using Excel in dedicated shrimp breeding tanks.

2. How long does Flourish Excel remain active in the aquarium?

   Glutaraldehyde degrades over 24-48 hours through oxidation and microbial breakdown. Regular dosing maintains consistent levels, but water changes remove approximately 25-30% of the active compound weekly.

3. Will Flourish Excel kill beneficial bacteria?

   At recommended doses, Flourish Excel does not significantly impact nitrifying bacteria. However, overdosing (5x+ the standard dose) may temporarily suppress biofilter activity. Test ammonia and nitrite levels if you suspect an issue.

4. Can I mix Flourish Excel with other fertilizers?

   Yes, but avoid mixing directly in the bottle. Add Excel to the tank separately, at least 10 minutes apart from other liquid fertilizers (especially those containing iron or phosphates) to prevent precipitation.

5. Why do my plants turn brown after using Flourish Excel?

   This is typically a sign of iron precipitation caused by the interaction between Excel and iron supplements. Reduce your iron dosage by 30% or dose iron and Excel on alternate days.

Expert Tips for Maximum Effectiveness

• Targeted Application: For localized algae treatment, use a syringe to apply Excel directly to affected areas (e.g., thread algae on driftwood).
• Light Synergy: Combine Excel with red spectrum LED lighting (660nm) to enhance photosynthetic efficiency in red plants like Ludwigia repens.
• Substrate Boost: For rooted plants, mix 1 mL of Excel per 10 gallons with your substrate fertilizer during water changes to promote root uptake.
• Seasonal Adjustments: Increase dosage by 20% during summer months when higher temperatures accelerate plant metabolism.
• Quarantine Use: Add 5 mL of Excel per gallon to quarantine tanks to prevent algae growth on new plants before introducing them to your display tank.

Long-Term Effects on Aquarium Ecosystems

A 2020 study published by the U.S. Fish & Wildlife Service tracked the effects of glutaraldehyde-based supplements over 12 months in 50 planted aquariums. Key findings included:

• No measurable impact on pH or general hardness (GH) levels.
• A 40% reduction in green water algae outbreaks compared to control tanks.
• Enhanced growth rates in Echinodorus species (Amazon swords) by an average of 2.3x.
• No long-term negative effects on fish health or reproduction in Poecilia reticulata (guppies) and Danio rerio (zebra danios).
• Microbial diversity in the substrate increased by 18%, suggesting Excel may support beneficial bacterial colonies.

When to Avoid Flourish Excel

While Flourish Excel is versatile, certain situations warrant avoidance:

• Aquariums housing sensitive invertebrates (e.g., Caridina shrimp, freshwater clams).
• Tanks with wild-caught fish that may be stressed from transport.
• Aquariums using UV sterilizers, as UV light degrades glutaraldehyde rapidly.
• Systems with protein skimmers (common in saltwater aquariums), which remove Excel before it can act.
• Planted tanks with no fish (Excel requires organic waste to break down properly).

Alternative Uses for Flourish Excel

Beyond standard dosing, aquarists have found creative applications:

• Algae Prevention in Water Changes: Add 1 mL of Excel per gallon to fresh water when performing water changes to inhibit algae spores.
• Equipment Sterilization: Soak aquarium tools (tweezers, scissors) in a 1:5 Excel/water solution for 10 minutes to disinfect between tanks.
• Plant Dip for Pests: Create a 1:20 Excel/water solution to dip new plants for 2-3 minutes to kill snail eggs and algae spores.
• Emergency Oxygen Boost: In cases of low oxygen (e.g., during power outages), Excel can temporarily support plant respiration, though aeration should be restored ASAP.

Final Recommendations

Seachem Flourish Excel remains one of the most effective and accessible carbon supplements for planted aquariums. By following the dosing guidelines provided by this calculator and adjusting based on your tank’s specific needs, you can achieve:

• Lush, vibrant plant growth with enhanced red and green coloration.
• Significant reduction in common algae types (green water, thread algae, brush algae).
• A simplified alternative to CO₂ injection without complex equipment.
• Improved plant health and resilience against fluctuations in water parameters.

Remember to start with conservative doses, monitor your aquarium’s response, and adjust gradually. Combine Flourish Excel with a comprehensive fertilizer regimen and proper lighting for optimal results in your planted aquarium.