My boyfriend and I have a 12 gallon nano cube. The pump isnt the best one in the world, but it works for now. However, we went onto the JBJ Nano Cube website and it was selling an "upgrade" to the pump. So we bought it and figured if anything, we'd keep it incase the one in there went out. So tonight, we got home and I wa feeding them and then i noticed that the food wasnt circling very well. We took the pump out and it wasnt working. We got the JBJ pump (the SP 1300) and the little green tube running from our current pump to the power head doesnt fit on the new one........ so how does this work? Do we need to make adjustments? Is this the wrong thing to try and replace with? I need help!

Thanks!