Check Valve and Bubble Counter Questions

[markstr]

I am setting up a new Tank and have an Ehiem #2028 and am interested
in getting some Check Valves for this .

Is this the sizing I need on this. 3/4" FPT W/ 3/4" MPT x 5/8 ?????

Best Place to get em' ?????

Also need a Bubble Counter for my Pressurized System...
Will this Work?

1" PVC Clear Tubeing W/ 1" Slip to 1/2" FPT adapter on other end..

Any info. would be Appreciated!!

Thanks...........