Air Pump Question

Sorry folks another question from me, I had a little leak back though the non-return valve on my air-line for safety's sake could I have two non-return valves in the air-line. Thinking of putting one just above the waterline.

I think I'd fit a replacement as well as an extra one; two new valves. And just to check - you have fit the current one the right way round?

Another thing you can do, if you haven't already done so, is to put the pump higher than the water surface. My betta's tank is on a kitchen worktop and the air pump is suspended from a hook in the base of the wall cupboard above the worktop and to the side of the tank (so it can't fall in  )