Bicarbonate of Soda

[Russ Little Pond]

I use Bicarbonate of Soda from Tesco`s and its contains a raising agent E500(ii) some information on it - http://myadditives.co.uk/archives/25592

How may it effect fish ?

Russ

[Manky Sanke]

Russ,

Don't worry about E500. There are three forms of sodium carbonate; sodium carbonate itself, sodium bicarbonate and sodium sesquicarbonate. They are chemically similar and the different names just refer to how many sodium molecules are combined with either carbonate or bicarbonate. E500 encompasses all three. E500(ii) refers to the sodium bicarbonate form so I guess it has to appear on the label to comply with food labelling regulations even though it says "this tub of sodium bicarbonate contains a food additive called sodium bicarbonate".

As to their effect on freshwater fish such as koi, both sodium and bicarbonate/carbonate are naturally present, and essential, in their bloodstreams.

Sodium is taken up by the chloride cells in the gills as they pump ammonia out (by an exchange process called an ion pump). It then helps regulate potassium levels so sodium is natural and necessary in the environment. Carbonate/bicarbonate is used to regulate blood pH and also remove carbon dioxide (by another ion pump) so that is necessary too.

[Russ Little Pond]

Manky

That makes for interesting ready.

I tip my virtual cap to you.

[Manky Sanke]

Thank you,

I've got a fascinating animation of the exchange process that shows how it all works. I wish I could share it but it came as a part of the course literature for a Koi Physiology course I took a couple of years ago so it's copyright.