Air pump "tee" issues

[Nicho]

I set up my air pump above my 11g and my 5g, and used a "t" joint close to the pump unit. It's only pumping air through to one aquarium... How can I stop this and even it out?

 

[jbird79]

They sell a valve at the store. The reason its only goin to one tank is the air is goin to take rhe path of least resistance