Fish Air Pump Question?

I currently have an Aquatic Gardens Air Pump 2000 that runs into a 4 way gang valve split. From there, two lines go to undergravel filters and the other goes to a bubbling treasure chest. I just got a bubble wall for the aquarium but noticed that when I hooked it up, the air flow in all connections reduced considerably. Is there a problem with my connections or is the pump not strong enough? I fhte pump isn't strong enough, can someone recommend a good, strong, inexpensive pump to control all 4 of these? Thanks.