I have found it takes 3 days - 5 weeks, so my question is, how long will it take a small sponge filter to seed? I have it sitting in my 180g sump with a air pump running it, and i want to move it to an established 8g tank (changing to a more shrimp friendlier filter) as soon as possible. I just don't want something to happen, and i lose $100 worth of shrimp. I was thinking a week, but i thought i would double check.