i had them in for 2 days about a month ago. i took them out bcuz they made alot of waste. i keep them in a jug and feed them algae tablets. well the other day i looked in my tank and i saw what looked like poop. but then on closer inspection, it moved. i looked closer there was about 5 incredibly small shells with snails in them acting quick i flung them into the intake tube and listened for the satisfy cracking sound that i assume means they got distroyed. not exactly the smartest thing i couldve done but oh well. i looked for more but i didnt see any. than i remebered the meds i havve that says it kills inverts. its an algae killer and on the back it says do not use in a tank that contains inverts such as clams crayfish shrimp etc. so i put some in as directed. if i keep this up will it exterminate them????