How do I make my apple snail stop reproducing even though the only large in tank?

There are a few different techniques you can use.

1. Separate the male and female apple snails. This is the most effective way to stop them from reproducing. You can do this by using a divider in the tank, or by moving one of the snails to a different tank.

2. Use a chemical reproductive inhibitor. There are a number of commercial products available that can be used to inhibit reproduction in apple snails. These products typically contain hormones that prevent the snails from producing eggs or sperm.

3. Control the water temperature. Apple snails are more likely to reproduce in warm water. By keeping the water temperature in your tank below 75 degrees Fahrenheit, you can help to discourage reproduction.

4. Provide plenty of food. Apple snails are less likely to reproduce when they are well-fed. Make sure to provide them with a variety of fresh foods, such as vegetables, fruits, and algae.

5. Add aquarium salt to your water. Aquarium salt is known to inhibit the reproductive process in apple snails. Add 1 teaspoon of aquarium salt per 5 gallons of water to your tank.

6. Reduce the amount of light in the tank. Apple snails are more likely to reproduce in bright light. By reducing the amount of light in the tank, you can help to discourage reproduction.

7. Remove the eggs from the tank. If you see any eggs in the tank, remove them immediately. This will help to prevent the eggs from hatching and producing more apple snails.