Ok, I have two small world filters in two tanks and one air pump. I can't get the pump to pump air to both filters and I can't figure out why. I have a t-valve to split the two airlines. I also have a small valve to control air flow. I thought with the air flow turned down there wasn't enough air coming through to make it to both filters so I removed the air control valve and it was full blast in one tank and nothing in the other. It's a pump for up to 10 gallons so it should be strong enough. I don't understand why it air isn't getting to both tanks.