There are many many types of nerite snails on the market right now. They're becoming more and more popular in the freahwater world mostly for two reasons.
-they are amazing algae control
-their young do not survive in freshwater
They can vary in size. Some of the horned species max out at only half of an inch while others can grow beyond two inches in diameter. They "one inch per gallon rule" loosley applies to snails in addition to fish. If you post what species you'll be getting, I can help you more with the "how many" aspect. What size is the tank? Please list the number and species of the current inhabitants.
When the algae is "gone", you can toss in an algae wafer or two. Here is an example of some algae wafers:
http://www.petsmart.com/product/index.jsp?productId=2754930
-tetrabettaguy97
-they are amazing algae control
-their young do not survive in freshwater
They can vary in size. Some of the horned species max out at only half of an inch while others can grow beyond two inches in diameter. They "one inch per gallon rule" loosley applies to snails in addition to fish. If you post what species you'll be getting, I can help you more with the "how many" aspect. What size is the tank? Please list the number and species of the current inhabitants.
When the algae is "gone", you can toss in an algae wafer or two. Here is an example of some algae wafers:
http://www.petsmart.com/product/index.jsp?productId=2754930
-tetrabettaguy97