I got a used filter about a week ago for my 20 gallon tall.. After a started up the tank the first day I got it , the next day I went in got 9 Ghost Shrimp ....The filter I have on it is a Regent AquaTech 30-60 gallon 2 way Filter..Now every one to two days I loose a Ghost Shrimp...And when I wake up the dead ones are on the filter suction tube...This this filter to strong for any Shrimp