No you don't need to suck them out, and Kalkwasser paste is safe as long as you don't use a huge amount at once. Although I have used an entire bottle of Joe's Juice at one time with no ill effects but I don't recommend it, that was my last ditch effort to clear the several thousand aiptasia I had in my system. I used one bottle every weekend for four weeks and finally got ahead of the aiptasia now I just have to treat every month or so with 5ml or so to get the ones that come from the ones I can't reach as they start to spread