Precipitation Question (Baking Soda + DOW Flake)

[chem_fun]

Randy,

I made both the DOW Flake and the Baking Soda. The Ca worked great to raise my Ca levels, however when I add the bicarb, I instantly get a large precipitate. (Ca Carbonate I’m assuming)

Just for fun I added baking soda that had not been dried. No precipitate. I’m not sure what would have caused the baking soda to change just by placing it in the oven.

Any thoughts? I’ll probably remake another gallon of baking soda solution tomorrow and see if I get the same results.

Thanks.

-Scott

[Randy Holmes-Farley]

When you add high pH additives, like baked baking soda, you get an immediate cloud of magneisum hydroxide where the additive went in. That is normal and should quickly redissolve as it mixes in and the local pH drops. If it does not redissolve and the tank stays cloudy, that is a more serious concern.

[chem_fun]

It didn't 'cloud' the water, as the precipitate formed in big chunks.

Wow, this would really vouch for the need for the epsom salts.

If I get the cloud every time, is this ok?

[Randy Holmes-Farley]

How much are you adding at once?

Do the chunks settle out, or eventually dissolve?

[chem_fun]

Any ammount that I add creates the precipitate. adding baking soda out of the box did not.

I'm not sure if the precipitate disolved or not, as I let them settle and then went to school. I suppose I could add more and see what happens.

Though I did do my tests again, and I think my dKh is at about 11 and my Ca is at 500. So if I add any more...It's not going to be a lot.

[Randy Holmes-Farley]

OK. It is possible that you precipitated calcium carbonate (which is not optimal), but more likely magneisum hydroxide (which is normal).

In any case, there's no reason to not use the baking soda itself as long as the aquarium pH does not get too low. Adding it to a high flow area might also minimize the precipitation.