black mystery snails

Question
I have a ten gallon freshwater tank with some tropical fish and I had 2 black mystery snails.  Well the smaller of the two snails had become very inactive in the past few weeks although it continued moving to different areas of the tank.  The last 3 days it stayed in the same spot I finally decided to check it and while removing him he fell out of his shell into the water.  Will this harm my other fish.

Answer
Hi Nicola;

As long as you removed him it should not be a problem. A dead snail is generally not going spread disease to your fish but it will contribute toxins that can make them sick. The toxins could still remain even after you remove the body. I would make a 25% water change right away. A weekly water change is necessary in all tanks anyway. I would do an extra one just to be sure everything's okay.

At Your Service;
Chris Robbins