Whats the dial next to the washing tablet space for???

Hi Andy, that dial is the setting for the rinse aid.The rinse aid only really helps the drying.If you are getting a poor wash, I would check the spray arms first,if the holes are blocked,they will not rotate so give a poor wash.You may get a poor rinse which leaves silica (looks like sand) on the upturned bases of your mugs.
Hope this helps. All the best.

FOXY
September 2008