So I got home from class and saw my fish gasping for air, I recently just replaced my HOB filter with a reactor. My reactor out put to put the water back into the tank is underwater so the only thing I could think of is shorten the line so the out put from the reactor is hitting the air first just like the HOB filter was ????? Is that the problem and did I fix it please let me know guys thanks. The reactor has been in like 5 days and the fish have never done this before