I made a DIY refugium similar to the CPR HOB aquage but mine is around 5 gallons and sits on the stand behind my 10 gallon. I intake is 1/2" tubing and the output is 1" tubing back into the tank pretty much like the CPR. My problem is that i am getting a lot of bubbles coming back into the tank. I tried to put a T fitting with the top open to the airi nstead of just an elbow on the output but it didn't help much. Is there any way to eliminate the bubbles?