Tetramin 2 week holiday food is a healthy nutritious diet to sustain all tropical fish for up to 14 days. Features: Does not cloud or pollute the water. Patented formula with delicious Daphnia, essential vitamins trace elements and minerals. Features tetras unique active formula for healthy fish. Easy to feed, simply remove the freshness seal and drop the block in. Pack contains one block suitable for an average of 30 small tropical fish Multiple blocks can be used Blocks can be left in the aquarium even when normal feeding resumes Existing plaster blocks are “old school” technology that can wreak havoc on your water quality! Tetra’s innovative gel feeder blocks contains no plaster and allows your fish to nibble away at their own pace instead of dissolving regardless of the demand for food.