API CO2 Booster

• Liquid carbon, not a gas – API describes it as an organic compound that slowly releases CO2 plants can absorb through the water, rather than a pressurised gas dosed through a diffuser.
• One dose a day – 1 mL per 10 US gallons (38 L), measured with the API Dosing Cap fitted to the bottle.
• Does not alter pH – API states it is safe for use with freshwater fish and will not shift aquarium pH.
• Shrimp-safe at the label rate – API states it is safe for use with shrimp when dosed according to directions; that claim does not extend to overdosing.
• Works with or without pressurised CO2 – API markets it for use alone or alongside an injected CO2 system, for tanks not yet running pressurised gear.
• Under 1c per litre – see Cost per litre below. Both bottle sizes work out to a fraction of a cent per litre dosed.

API's label rate, transcribed from the product page:

Applied at the same 1 mL : 38 L ratio across common tank sizes:

Dose using the API Dosing Cap supplied on the bottle, added directly to the tank once a day rather than saved up and added in one weekly dose.

API's safety data sheet for this product exists but returned an access error when this page was checked, so we cannot transcribe a verbatim ingredient list here. Nothing on API's product page names the active carbon compound. If you need the exact composition, API Fishcare's customer service can supply the SDS directly.

API does not publish a "treats X litres" figure for this product, so the figures below are worked from API's own dose rate: at 1 mL per 38 L per day, a bottle's millilitres divide out to a total volume of daily dosing capacity.

Both sizes work out to well under a cent per litre dosed. Per millilitre, the 473 mL bottle is the cheaper of the two – worth buying if you're dosing more than one tank, or a single tank over about 100 L.

Suitable for:

• Freshwater planted aquariums run without pressurised CO2
• Planted tanks already running pressurised CO2, as a supplementary carbon source
• Shrimp tanks, dosed strictly at the label rate

Not suitable for:

• Marine, reef or brackish aquariums – API makes no saltwater claim for this product
• Complete plant nutrition on its own – API recommends pairing it with a fertiliser such as API Leaf Zone "for complete plant care", which tells you this bottle supplies carbon only, not macro or micronutrients
• Dosing above the label rate around shrimp or other sensitive invertebrates

• Keep out of reach of children.
• Use the API Dosing Cap to measure each day's dose rather than pouring by eye.
• Do not exceed the label dose, particularly in shrimp tanks.
• Store the bottle sealed, away from direct sunlight and heat.

• API Leaf Zone – API's own pairing recommendation, for the macro and micronutrients this bottle does not supply.
• Bioscape CO2 Reactor with On/Off Valve – for a tank moving up to a pressurised system this bottle can still supplement.
• API Quick Start – live nitrifying bacteria for a newly planted or recently disturbed tank.
• API Freshwater Master Multi Test Kit 5 in 1 – keep an eye on pH and ammonia while you dial in a new dosing routine.

This is a consumable, so no manufacturer warranty period applies. That does not affect your rights under the Australian Consumer Law: if the product is faulty, unsafe or not as described, you are entitled to a remedy.

Both bottle sizes ship as standard freight.

Does API CO2 Booster replace a pressurised CO2 system?

Not necessarily. API markets it for use either on its own in a low-tech planted tank, or alongside an injected CO2 system as a supplementary carbon source. Which approach suits your tank depends on your plant selection and lighting.

Will it change my aquarium's pH?

API states the product will not alter pH levels in aquariums, unlike a pressurised CO2 system, which can lower pH as dissolved CO2 rises.

Is it safe with shrimp?

API states it is safe for use with shrimp when dosed according to directions. That claim is tied to the label rate of 1 mL per 38 L daily – it is not a guarantee at higher doses.

How much does a 237 mL bottle treat?

At API's rate of 1 mL per 38 L once daily, 237 mL is 237 individual doses. Spread across one 38 L tank dosed daily, that's 237 days; spread across a larger volume, fewer days at a larger daily dose.

Can I use it in a saltwater or reef tank?

API makes no saltwater or reef claim for this product. It is sold and labelled as a freshwater planted-tank treatment.

What is actually in the bottle?

API's product page does not name the active carbon compound, and the safety data sheet could not be retrieved when this page was checked. We have not guessed at the chemistry – contact API Fishcare directly if you need it confirmed.