Seachem Flourish Excel

• Works without a CO2 system – supplies bioavailable carbon that many plants can use in place of dissolved CO2 gas.
• Also suits CO2-injected tanks – dosed alongside pressurised CO2 in demanding, higher-light setups as a supplementary carbon source.
• Helps some algae types – commonly used as part of an algae-control routine, though it is not an algaecide.
• Keeps iron plant-available – its reducing action helps hold dosed iron in the ferrous (Fe²⁺) state plants can absorb.
• Six bottle sizes – from a 50 mL trial size up to a 4 L bulk bottle for larger collections of tanks.

The dose is the same per litre regardless of bottle size, so pick a size for how long you want between refills rather than tank size alone. Every size works out to under 1c per litre treated at the daily maintenance dose – the 4 L bottle is the cheapest per litre of the six, the 50 mL bottle the most expensive, though even the smallest bottle costs a fraction of a cent per treated litre. A single 100 L tank dosed daily at maintenance rate goes through roughly 2.5 mL a day, so a 250 mL bottle lasts about three months; step up to 500 mL, 2 L or 4 L for multiple tanks or longer intervals between orders.

• First use, or after a water change over 40%: dose 5 mL per 40 L.
• Ongoing maintenance: dose 5 mL per 200 L daily, or every other day.
• Each thread on the cap measures approximately 1 mL for fine adjustment on smaller tanks.
• Sensitive species such as Anacharis (Egeria) can react to daily dosing – switch to every-other-day if you see leaf damage, and reduce the dose rather than stopping altogether.

• Suitable for freshwater planted tanks run with or without pressurised CO2.
• Not a substitute for macro and micronutrient dosing – Excel supplies carbon only; plants still need nitrogen, phosphorus, potassium and trace elements from products such as Flourish, Flourish Nitrogen and Flourish Iron.
• Some stem plants are sensitive to daily dosing at full rate – start conservatively and watch new growth for the first week.

• Seachem Flourish – the base trace element supplement Excel is designed to be dosed alongside.
• Seachem Flourish Iron – for red and iron-hungry stem plants.
• Seachem Flourish Nitrogen – nitrogen dosing for demanding planted tanks.

Seachem doesn't publish a fixed warranty term on consumable dosing products; your purchase is still covered by the consumer guarantees under Australian Consumer Law. Ships as a standard parcel – no cold chain or special handling required.

Can Flourish Excel replace CO2 injection completely?

In low-to-medium light tanks, yes, many aquarists run Excel as their only carbon source. In high-light or heavily planted tanks, pressurised CO2 still delivers more carbon than liquid dosing can match, and Excel is better used as a supplement in that case.

Will Excel hurt my shrimp or fish?

Dosed at the label rate it is broadly considered safe for fish. Some aquarists report sensitivity in shrimp and in soft-leaved plants like Vallisneria and Anacharis at full daily dose – dose to the lower end of the range and watch your livestock and plants for the first few doses.

How long does one dose last?

Seachem states the carbon remains available to plants for up to 24 hours, which is why the maintenance dose is applied daily or every other day rather than weekly.

Do I still need to dose Flourish and Flourish Iron?

Yes. Excel supplies carbon only – it does not contain nitrogen, phosphorus, potassium or trace elements, so a full-spectrum planted tank still needs a base fertiliser alongside it.