Preservative E300


Ascorbic Acid

Weight 10g 50g

SKU: N/A Category:


Ascorbic Acid, Pure

Other names

Vitamin C, L-ascorbic acid, Ascorbate

CAS Number 50-81-7

EC Number  200-066-2

E number  E300

Chemical formula C6H8O6

Solubility in water 330g/l (20 °C)


0.5g of E300 for every 500ml of solution protects against growth of bacteria and lowers solution’s ph protecting against disintegration of compounds.

It’s recommended to use E300 together with E202 which impedes the growth of mildew and fungus.

It is the safest way of conservation for the users and 100% safe for the living organisms and plants in aquariums. Optionally, you can add 2ml of carbon (e.g., easy carbo, liquid carbo) for every 500ml of solution.

10g E300 is enough to conserve 10 liters of  solution

Store in dark place, in room temperature.

In order to measure the required amount you can either use a scale, a measuring jug (with milliliters), a teaspoon or a tablespoon. If you want to use spoons, it is important that you use the same spoon for all of your mixtures. The size of the spoon is not that important – it is the maintenance of the proportions of all of the ingredients that matters.

Just to give a rough guide: 1 teaspoon = approximately 5g, 1 tablespoon = approximately 15g.

What also needs to be remembered is that every chemical compound has different maximum solubility in water and that the values given above are accurate for distilled water. The maximum solubility in RO water will be slightly lower; solubility in boiled water will be even lower (if you want to use boiled water, we recommend you to boil it for 3min and than let it drop to room temperature).

It is worth mentioning that saturation of a solution of one salt will decrease the solubility of another salt added to the same solution.


Good To Know

Ascorbic acid, vitamin C, E300 (acidum ascorbicum)

organic compound belongs to a group of unsaturated polyols. It’s necessary to living organisms for functioning. It’s a vitamin therefore for humans and animals it needs to be delivered with food. E300 is also an antioxidant used as a food additive.

Ascorbic acid naturally occurs as a compound with L configuration in the side chain and with D configuration in the furan formation. Under methanolic NaOH solution ascorbic acid goes through the process of epimerization to erythroboic acid (E315) which can be differentiated due to different side chain configuration. The L-ascorbic acid is sometimes mistakenly called ‘levorotatory vitamin C’ due to its relative configuration confused with optical rotation. In fact, L-ascorbic acid turns polarised light wave to the right. The D-ascorbic acid, on the other hand, is an antioxidant, but it has no biological function – it does not work as a cofactor, therefore it is not a vitamin.

Vitamin C was first isolated in 1928 by Hungarian biochemist Albert Szent-Györgyi from adrenal gland tissue, orange juice and then from peppers. He provided evidence that the newly discovered compound has antiscorbutic properties and called it ‘hexuronic acid’. In 1933, Haworth and Hirst came up with the acid’s structure. Also, Haworth, and independently Reichstein with colleagues, described synthesis of its both enantiomers. In the same year, Szent-Györgyi and Haworth proposed its name to be changed into ‘ascorbic acid’ in order to reflect its antiscorbutic properties. In 1937 both scientists received the Nobel prize for their work on vitamin C: Szent-Györgyi in the field of Physiology or Medicine and Haworth in the field of Chemistry.

Additional information

Weight N/A
Product Weight

10g, 50g


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