As a guide one block placed in a 45 litres (10 gallons) aquarium should be sufficient to supplement the diet of 10 – 15 average aquarium fish for approximately 2 weeks.*

*This assumes a water temperature in the range of 20°C – 25°C. Lower temperature or highly alkaline water will inhibit dissolution – higher temperature will accelerate it.

Remove any part of the undissolved block on your return. It is advisable to change approximately 10% of the aquarium water weekly and to circulate the water by a filtration or aeration system to assist dissolution of the block. The introduction of aquarium plants will provide an alternative source of food whilst you are away.