I was in the LFS today and mentioned to one of the employees that I had a tank with play sand and that my plants weren't doing very well. He suggested using the Flourish Excel Organic Carbon. I think he called it dissolved carbon. My tap pH runs about 6.8 to 7.0 but this particular tank stays around 6.4 so I don't want to do anything that lowers the pH any further. Will it have any effect at all and if so what will it do?
