Quote:
Originally Posted by jlm9679  Regarding the oyster/egg shells, what is their function within the substrate? - I have seen it recommeded, but no reason given for it! |
For tanks with extremely softwater (GH <4 and < 70 ppm CaCO3), I suggested that hobbyists add a little calcium to their substrates or to the water. If your water has a normal water hardness, then you probably don't need the additions.
This information is in my book (pp. 86, 137, and 185).