In principle the experiment is meant to investigate plant growth under various conditions, some good, some less so. A plant not growing as quickly as expected or dying off might be the result of environmental conditions that are being recorded. In this case it is not a failed experiment, just one of the possible outcomes of the experiment. In fact, these results are crucial to the goal of understanding plant growth and development. If you have reason to believe another factor might be at play (e.g. a hydroponics defect or poor germination), contact AstroPlant support.