I have several clams in my 10 gal fish tank with 2 5in goldfish. Four have died and I am wondering if it is too crowded. I am collecting them for bait. I have to take out two dead ones today, they are stinking up my room. Whats worse is we are having a guest over tonight. I am airing it out right now. How do I stop the RCD [random clam death]?