“While it is tremendous to see the root system of your plants, you need to cover the nutrient solution to prevent direct light from promoting algae growth in the reservoir. ✓    If the lid on your Kratky system isn’t tightly secured, then harmful bacteria and pathogens can easily enter the system and kill your plants. ✓    Since most Kratky method systems are meant not to be opened again after they are built, you need to be extra careful to get everything mixed properly and tightly secured during the build phase.”