To ensure your arrangement of 50 red roses in a glass vase stays fresh and beautiful, follow these care instructions:

1. **Trimming Stems**: Upon receiving the roses, trim the stems at an angle with sharp scissors. This allows for better water absorption.

2. **Clean Vase**: Use a clean vase and fill it with lukewarm water. Add any provided flower food or preservatives to prolong the roses' lifespan.

3. **Water Level**: Keep the vase filled with enough water to cover at least half of the stems. Check the water level daily and top up as needed.

4. **Location**: Place the vase in a cool spot away from direct sunlight and heat sources. Avoid placing them near ripening fruits, which release ethylene gas and can accelerate wilting.

5. **Changing Water**: Change the water every 2-3 days to prevent bacterial growth. Before adding fresh water, re-trim the stems to maintain water uptake.

6. **Pruning**: Remove any wilted or yellowing leaves and petals from the stems to keep the arrangement looking fresh.

7. **Enjoyment**: Display your arrangement in a prominent location and enjoy the beauty and fragrance of the roses. Remove any spent blooms promptly to encourage new growth.

By following these care tips, your arrangement of 50 red roses will stay vibrant and lovely for as long as possible, bringing joy to your space.