Dried leaves, barks & seeds
In the natural habitats of shrimps, you can always find leaves that are dropped into the streams and water bodies. The leaves decompose over time, releasing its goodness of minerals, vitamins and at the same time, get munched on by the critters.
Oak leaves contains tannins and have ability of gently lowering PH of water.
1-2 leaves in about 30 liters of water.