CarboCalcium gone bad??

[Roca1357]

Got a bottle to try out since I couldn't find any all for reef locally. However, this has some brown gunk growing in it. I was under the understanding that at this concentration of calcium formate it should not be able to support bacteria growth in the bottle. Anyone seen this before?

 

[Randy Holmes-Farley Verified Community Expert]

Might be a chemical precipitate rather than an organism growth. It is probably fine.