I got it a couple days ago and it was used but fully functional with a rio 600 pump. I had 2 tubes on the pump to put air in but the skimmer cup even with the O-ring all the way to the bottom filled up with water and started leaking within half an hour so I took away one tube but it is still doing this. How can I fix it? Also can I grow chaeto in it and use it as a filter with no other filters? Thank you!

