Problem solved.
First, it does not matter if you put the strainer vertical or lay it flat.
Second, Flowjet are sending me a replacment strainer, A newly designed one that fits onto the pump on the inlet valve Dur to my new strainer having a leak.
You dont need a special wrench to tighten them because they should be fully sealed by turning them by hand.
I spoke directly to the product designer at Flowjet, I had made an error in setting the system up in that when I mounted the strainer on the stainless steel sheet the outlet barb was ponting up, which ment I had to loop the 1/2" Hose to get it into the pump, So the air lock from the strainer expanded into the hose and because my hose was looped it meant the pump could not get rid of the air lock.
The strainer should be positioned below the pump and the hose from the strainer should be on the same level as the pump or it should go up. But it should never looped like I did, the hose going up then back down before entering the pump. You have been warned.
Nel.