Salt with Anti caking agent (551) (Is it okay for tanks)

[Ali.]

Hi

We got a bag of non iodized salt from the supermarket just to find that it contained an anti caking agent 551 which is Silicon dioxide. This comes from sand or Quartz. It is also used in artificial sweetener, anti-caking agent, thickener and stabiliser in beer, confectionary, sausages, dried milk and a huge range of foods.

What I want to know is, is this anti caking agent okay for fish tanks. Will my fish be okay if I add the salt to my tropical fish tank (not marine)? Or should I just return it and look for another alternative?

[Ira]

Yeah, should be fine. Since your tank's glass is made from it as well as the silicone sealing it, possibly the sand in the bottom...It's one of the most inert substances you'll find anywhere.

[Jennifer]

If you dissolve it in a bunch of water and leave it to sit over night you can just carefully pour off the salt water and leave all the silt behind in the bottle (that is, if you don't want all the silt in your tank) altough if it is a very small quantity you probably wont notice much. I make saturated salt solutions (for lab work) and I dissolve a kilo of cheap salt in 1 litre of water, and there is a thick layer of silt at the bottom the next morning! Not harmful though.

[Ali.]

Thanks very much for that advice, you both have put my mind at rest about using the salt. As I need to put one teaspoon per four litres for some killies I don't think it will leave much silt at the bottom.