While you can add water from the DT, that alone will not be adequate to cycle the tank. The type of bacteria required to cycle the tank is primarily attached to surfaces within the tank rather than floating in the water column. Bottled bacteria can work, but it usually takes several days to a week to reach adequate population. During that time, you will need to monitor your ammonia level.All the things inside are pipes, I'll add filter media but can I add a bit of water from my tank too? I'll need more bottled bacteria anyway