Sodium percarbonate

$7.00

Weight	Price	Price per kg	vs 500 g
500 g	$7.00	$14.00	—
1 kg	$11.00	$11.00	−21 %
3 kg	$22.00	$7.33	−48 %
5 Kg	$35.00	$7.00	−50 %

$2.33 × 3 with no fees Klarna.

This pure sodium percarbonate releases active oxygen as soon as it dissolves in water. It is used to re-oxygenate a pond in an emergency, to eliminate filamentous algae and to disinfect equipment, and the dosage in an aquaponic system is 10 g per m³.

Ref. PCS-0500·Pond water treatment

Weight : 500 g

500 g

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The summary

What you receive: pure sodium percarbonate with an active oxygen content of over 13%.
In aquaponics: 10 g per m³ re-oxygenates the water in an emergency without harming the biofilter.
In an ornamental pond: 30 g per m³ treats filamentous algae, without exceeding 50 g.
Before each application: a pH below 8.6, the powder dissolved in a bucket, and aeration running.

Active oxygen powder for emergencies, pond algae, and equipment

Sodium percarbonate is a white powder that releases active oxygen as soon as it dissolves. In water, it breaks down into sodium carbonate and hydrogen peroxide, which in turn decomposes into water and oxygen. It can be used to re-oxygenate water in an emergency, to eliminate filamentous algae from a pond, and to disinfect equipment, leaving behind neither chlorine nor any metals.

🫧 Active oxygen in the water

This percarbonate contains more than 13% active oxygen, equivalent to more than 27% of its weight in hydrogen peroxide. In a live system, this peroxide breaks down quickly, with a half-life of around 30 minutes, and each gram releases 0.47 g of oxygen. The carbonate, however, remains in the water: it raises KH by approximately 0.4 degrees per 10 g per m³ and increases pH, so measure the pH before each application.

Emergency oxygen

During a power cut, 10 to 20 g per m³ quickly introduces dissolved oxygen, buying time to restart the aeration.

Filamentous algae

In an ornamental pond, 30 g per m³ treats filamentous algae. Do not exceed 50 g per m³, and wait 3 days before a second application.

Equipment and trays

Outside the system water, a warm solution disinfects nets, pipes, growing baskets, and quarantine tanks before rinsing.

Safety glasses and gloves when handling the powder

The pure powder is classified as oxidising (H272), harmful if swallowed (H302), and liable to cause serious eye damage (H318). Wear goggles and gloves when weighing and dissolving it, avoid inhaling the dust, and store the sealed sachet in a dry place, away from all combustible materials and acids. Never add the dry powder directly to the pond: dissolve it first in a bucket of pond water, then distribute the solution.

Maintaining continuous oxygenation with a pond aerator

Percarbonate can help you out during a power cut, but the oxygen it releases only lasts for as long as the peroxide decomposes, a matter of hours. A pond aerator provides a continuous supply and protects your fish on warm nights, when water holds the least oxygen. Keep the percarbonate in reserve for the day the aerator stops, and verify the result with a dissolved oxygen test.

🌱 In aquaponics, a low dose

An aquaponic system cannot be treated like an ornamental pond, as hydrogen peroxide also acts on the bacteria in the biofilter and on the roots of the crops. Above 5 mg of peroxide per litre, approximately 18 g of percarbonate per m³, nitrification slows down. Trials in hydroponics have also recorded a marked growth delay at 4 mg of peroxide per litre, equivalent to around 15 g of percarbonate per m³. In your system, if it supports crops, reserve this product for emergency oxygenation at 10 g per m³, and carry out any stronger treatment in a separate tank. The article on the nitrogen cycle explains why your biofilter must come first.

🌿 Treating an ornamental pond

First measure the pH of your pond, because above 8.6 adding carbonate would raise the pH further, and with it the proportion of toxic ammonia. Then dissolve the dose in a bucket of pond water and spread it across the entire surface at the start of the evening, with aeration running. Isolate the biofilter and switch off the UV steriliser for 45 to 60 minutes, then restart the filtration. Do not feed your fish that day, and wait 3 days before a second dose. The article on pond algae in summer covers the causes that make them return.

🧺 Disinfecting the equipment

Outside the system water, percarbonate disinfects equipment moving between tanks: nets, pipes, growing baskets, and quarantine tanks. Dissolve the powder in hot water, leave to soak, then scrub, and rinse thoroughly before any contact with fish again. The reaction becomes significantly more active above 40 °C, so prepare the bath with very hot water. Keep the packet tightly sealed, in a cool, dry place, as the active oxygen is depleted by heat and moisture even when the powder shows no visible change.

Technical specifications

Composition

Formula: 2Na2CO3 . 3H2O2Sodium carbonate peroxyhydrate, CAS number 15630-89-4.
Active oxygen: More than 13%That is over 27% of the weight as hydrogen peroxide.
What it leaves behind: Carbonate, water, oxygenNo chlorine, no phosphate, no metals.
Effect on KH: +0.4 degree per 10 g/m³The carbonate remains in the water after the peroxide breaks down.
pH of a 1% solution: 10.4 to 10.7Measured at 10 g/L and 20 °C.
Appearance: Granulated white powder

Doses in water

Emergency oxygen: 10 to 20 g/m³In aquaponics, keep to 10 g/m³ to protect the biofilter and the roots.
Filamentous algae: 30 g/m³, 50 at mostOrnamental pond use only, treatment can be repeated after 3 days.
Limit in a cultivated circuit: Approximately 15 g/m³Beyond that, isolate the biofilter for 45 to 60 minutes.
Maximum pH before dosing: 8,6Above that, carbonate makes the ammonia in the water more toxic.

Safety and storage

Ranking: Oxidising, harmful, corrosive to the eyesMentions H272, H302 and H318.
Protection: Gloves and gogglesThe pure powder causes serious eye damage.
Storage: Sealed, dry, coolStore below 40 °C, away from combustible materials and acids.
Mixes: Never with another productDissolve it on its own, in fresh water or pond water.

To budget for separately

pH test: pH drop test
Oxygen test: Dissolved oxygen test

8 further specifications are available in the detailed view.

In the box

1 bag of pure sodium percarbonate, in the chosen size.

Active oxygen, pH, hazard statements, and storage: technical data sheet (version 1.2 dated 16/07/2026) and safety data sheet (revision dated 28/02/2024) for the product, available to download on this page. Biofilter threshold and peroxide half-life: Pedersen et al., 2010 and 2012. Pond doses: product directions for percarbonate-based treatments. KH and peroxide calculated from the formula.

Documents & manuals

Official technical data sheet

It states the grade, active oxygen above 13%, pH of 10 to 11, bulk density, and maximum moisture content of the powder.

PDF · 277 Ko

Download

Safety Data Sheet (SDS)

It details hazards H272, H302 and H318, first aid measures, storage below 40 °C and toxicity for fish, daphnia and algae.

PDF · 1,5 Mo

Download

Estimate your
delivery time

Non-fragile powder, dispatched by tracked parcel from France. The 3 kg and 5 kg formats are heavy but compact parcels. Exact shipping costs and final delivery times are displayed in the basket once the address has been entered. Outside the European Union, import duties and taxes remain the responsibility of the recipient. Delivery times run from the date of dispatch, excluding public holidays.

Frequently asked questions

6 questions

6 key questions

Can it be used in an aquaponics system with plants?

Yes, at no more than 10 g per m³, for emergency re-oxygenation. Above 15 g per m³, hydrogen peroxide inhibits root growth, then slows biofilter nitrification at around 18 g per m³.

Treatment doses suitable for an ornamental pond have no place in a system carrying crops. If a fish needs treatment, do so in a separate tank, then return it to the system after the decomposition period has elapsed.

What dose is needed to oxygenate the water during a power cut?

Should the biofilter be switched off during a treatment?

Does percarbonate raise the pH and KH?

Yes, because sodium carbonate remains in the water after the peroxide has broken down.

Dose	KH added	Use
10 g/m³	+0.4 °dKH	Emergency oxygenation in aquaponics
30 g/m³	+1.1 °dKH	Filamentous algae in a pond
50 g/m³	+1.8 °dKH	Maximum dose in a pond

Do not treat above a pH of 8.6.

How do you treat filamentous algae in a pond?

Sodium percarbonate and sodium perborate — are they the same product?

How much percarbonate for your water volume

Enter the water volume of your system or pond. The main calculation gives the emergency oxygenation dose compatible with a biofilter and growing beds.

Water volume

100 L50000 L

to re-oxygenate the water in an emergency, in aquaponics as well as in the pond.

Treatment of filamentous algae in ornamental ponds and isolated biofilters.

0 g

Emergency dose: 10 g per m³, below the biofilter limit. Algae treatment: 30 g per m³, reserved for ponds without crops, biofilter isolated for 45 to 60 minutes, pH below 8.6.

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Sodium percarbonate

The summary