Why is SeaKlear clarifier blue, and where does it go?

[Kes]

SeaKlear 'Natural' clarifier is sometimes mentioned in these forums, perhaps as one of the least-worst of the undesirables. It's a chitosan clarifier, and it's blue. I asked SeaKlear why it's blue, and is the dye (I assume that chitosan is colourless) biodegradable. They replied that the dye is 'an ingredient commonly used in personal care products such as makeup, skin care products, cleansers and hair care products. We cannot verify at this time if it is considered biodegradable.' Google intimates that the dye might be Brilliant Blue FCF. Google also intimates that these dyes are not readily biodegradable as that would negate the purpose of the dye quite quickly. In fact (good old Google) one of the methods to remove Brilliant Blue dye from water is... chitosan.

So if I use SeaKlear clarifier (and I have occasionally) is the water being dyed, or does the chlorine undye it, or what, and where does the dye go?

The SeaKlear MSDS is no help at all.

 

[JoyfulNoise]

Chlorine will oxidize most organic dyes. Organic blue dyes are highly susceptible to chlorine bleaching. Biodegradation occurs as a result of sunlight, water, and biological organisms acting upon organic and inorganic materials. Things in pool water don’t “biodegrade” … they are oxidized and destroyed by sunlight (UV), reactive oxygen radicals, and chlorine.

The blue dye is just that, dye. It serves no purpose other than to give the user the psychological confidence that they are adding “a chemical” to their pool and not just water. Other than that, it’s harmless.