Hello! I have a small two inch fantail goldfish in a 32 gallon tank with marineland 350 HOB filter. The filter output seems a little too strong. It created a strong current near the surface that blow my fish halfway across the tank. The current is from back to front and I tried hot glueing rocks to the filter's output but the rock won't stay. How do I dispense the flow? When my goldfish get bigger he will probably be fine, but right now I need to think of a way to dispense the flow. Please help!