15 Litre (1680g) Sack. 1680g (15 litre) sack. Below 10°C, stop feeding Tetra Pond Sticks and switch to Tetra Pond Wheatgerm Sticks. Tetra 15 Litre Pond Sticks Floating Fish Food. Tetra Pond Sticks are a complete food that has been formulated for use with all Pond Fish.