I found this on the saltwaterfish message board:
you can pick up those clams at your local fish market- even packed in ice
b4 you place in tank, just put in a bowl full of tank water until it spits, then place in your tank
1 per every 5 gallons and your nitrates will always remain low:joy:
Is this true? Do they eat nitrates?
Here's the website
http://www.saltwaterfish.com/vb/showthread.php?t=152707