Determining the weight of 100 CDs depends on whether only the CDs are weighed or if the CDs have sleeves or jewel cases. A single CD by itself weighs about 0.58 ounces. Therefore, 100 CDs by themselves weigh 58 ounces.
Plants need nitrates to develop green leaves. Nitrogen, potassium and phosphorus are the three major nutrients plants need to grow successfully. In particular, nitrogen is responsible for foliage development. Plants use nitrogen in the form of nitrates, which is nitrogen mixed with oxygen. They usually absorb nitrates from the soil.
Plants will absorb ammonia and nitrate. Planting a tank with very low <10 ppm of nitrate would not come out too well if the plants are fast growing. These are both nitrogen fertilizers, and one of the macro nutrients needed by plants. Lack of nitrogen usually leads to pale, almost white plants.