Changing filter cycles on Gatsby hot tub

[tomasaur]

I bought a used Gatsby tub a little while ago.  It seems that the filter cycle is always on, as there's always a pump running (not a big jet pump, it's the same one that runs water through the heater).  I found a users manual online http://jacuzzichino.com/manuals/Gatsby.pdf and it appears that you should be able to change the filtration cycle by pressing the light button for 5 sec and then scrolling through options that appear on the lcd screen.  This doesn't work on my tub, pressing any button for 5 seconds or more has the same effect as a momentary push. 

Any ideas out there? 
Thanks in advance,
Tom

[Jacuzzi Jim]

 Try pushing light btn then a temp btn. Worth a try..