i have a strong powerhead that just killed my nudibranch. It is the reef wave 45. I have a large 3 inch skunk cleaner shrimp, is he in danger of the powerhead? I also have a turbo snail and 3 astreas, are they in danger as well? Also if i were to get urchins and or starfish eventually, would they be in danger? Please help i dont want any more dead animals