Helium Filled Balloons with Collar Won't Float
My 12 inch balloons filled with helium and 5 inch 4 quad collar won't float. Can you tell me why?
Did you also fill the 5 inch balloons with helium or only the 12 inch balloon? If you filled all balloons with helium then the only reason I can think of would be that your balloons are not of helium quality, so that the helium leaks out quickly.
Other factors influencing the floating capability of helium are air pressure (the higher up above see level you live, the lower the air pressure gets, the less efficient helium is) and air temperature. If it's very cold in the room where you blow up your balloons, they might not float.
Hope that helps,