Find the lowest price for:       All ProductsAdditives & Supplements     1.0 (1)   Add a review Marc Weiss Blackpowder 4 oz.   BlackPowder 112 grams by Marc Weiss. Your living reef comes vibrantly alive with BlackPowder. Designed to maximize growth and color in everything from anemones to coral, sea apples to sea cucumbers, filter feeders to... Have a question? Ask the Experts! Compare Prices Product Spec Member Reviews Recommend to Friends Edit the spec Brand Marc Weiss Category Unknown Know it? Let us know! Something wrong in this page? Let us know! Related products: More Marc Weiss Additives & Supplements Other Additives & Supplements internal use: spec162 spec204