I have used the bc skimmer in my 3 bc setups. They take a few days to break in. What I found when I used it is to take the extra lime wood air stones that you get, and put them in the middle chamber so that they can soak. The "break in period" for these are that the stones need to be saturated. Just put the extra one that you have in the middle chamber so that it can absorb the water, and will be ready to go when you need to change them. That's what I always did, and always worked great from the get go.