no, but you should really know the wattage and color scale of your light to be successful. too little and the plants won't do well, wrong color scale and they will not be able to absorb enough light. too much light may warrant a need for CO2 or other fertilization. your water will not become toxic if they start to die, and you can always bring them back. if they completely dead and rotting, just throw them out, but you should be able to save them before that point.