OK I closed the splice valves either side of the pump and heater unit.
Disconnected the pump and both ends of the heater, no blockages in any of them and water came out clean as.
I have had the circ pump start and run for about a minute after power off (error msg still on panel) checked suction and it's pulling beautifully and from what I can tell it's pumping out the wetend fine.
I will hop in the spa tommorow and have someone come around and cut the power off for me so im in there when it restarts to feel what its like.
The swim spa is actually pretty clean , the video makes it look worse than it is. The debris you see is just at the other end of the spa where the swim jets are and they all work fine ( can only get 2 going with the HTR TOO HOT error but when I do have the error dissapear they going fine).
I've tried shorting jumper 29 to disable the Hester function but it still displays the same error.
At this stage all I can guess is there is a fault with the control unit or panel?.
I know one of them was replaced 12months ago before I moved in , trying to fine out what one and why now.