Торфом выложить все дно аквариума.
Вот инструкция, срисованная с упаковки
Directions
For best results cover the entire aquarium bottom, or cover preselected sites where plants will be situated. If an undegravel filter is used, place peat plates on top of filter. Cover peat plates with 3 to 4 inches of aquarium gravel. Nest plants directly over the peat plates so that they may root easily and securely.