I set up a 220 gal
tank about 2 months ago. Ever since I turned on the pump its had a lot of bubbles being produced mysteriously. The setup has two overflows that go into the top of a 50 gal
wet/dry bio balls. water then goes through the drip plate into bio balls then into the sump area. I have a protein skimmer in the sump but it does not produce bubbles in the outflow. It then goes into a 1" bulk head that is piped to my pump. Its an Iwaki IK1173. The outflow pipe then goes into a red sea canister filter with the pleated fabric filter(resembles an automotive air filter element). Then out into the pipes that goes to the outflow bulkhead on the aquarium to the flex pipe. I was told the pipe that connects the bulkhead on the sump to the intake on my pump needs to be hard pvc
, not silicone tubing like how it is now. somehow this creates a negative pressure that releases the dissolved gasses and thats where all the bubbles are coming from. I puchased all of the fittings and then found that the bulkhead fitting is jammed in so tight that I'm going to need to remove it and change it out, I just had it plugged to avoid draining my entire sump. So in the mean time I swapped out the silicone tubing with extremely rigid 1" black irrigation pipe. and saw no difference in the bubble production whatsoever. I also bypassed my canister filter and that didnt help. I'm just wondering if I even need to change the intake pipe to the pump or if there is somewhere else the bubbles could be produced? Has any one heard of the pump causing negative pressure that releases dissolved gasses? Is the pump to powerful, or do I need a longer intake pipe, or no pipe at all? also The bulk head on the sump is just open, but the water level is high enough that it doesnt whirlpool air in. Its about an inch and a half threaded pipe. should I have foam on it. or a 90 degree elbow would help? Thank you for your help, its driving me insane.