This might seem like a stupid question but I'm hoping for some help on using a commercial dishwasher. We just had one installed in our small restaurant this week and we were obviously excited (as we've been washing by hand for a year!) Then we put the first few loads in and.... they're not clean. The glasses have greasy marks, dirty ceramics are still dirty, cutlery is only 50% clean. Detergent and rinse aid are being used as I can see them going through the pipes, and the dishware comes out boiling hot and untouchable. But why isn't it very clean? Googling around, I've heard pre rinsing mentioned a couple of times. Is this a pre-requisite for getting things clean? We've put in items that are rinsed a bit and might have minor dirt on them - e.g. A bowl of ice cream that's been given a quick rinse but still some residue in the bowl - and it comes out almost exactly the same. Surely we're not supposed to rinse things til they're already basically clean? Or maybe I've misunderstood commercial washers and that's what you do in a restaurant? Despite the success of our business, my sister and I have not had any restaurant or bar experience and struggle with details like these so any info would be really appreciated. If it helps, the dishwasher is a Sammic X-50, which I believe is a hi-temp. Thanks in advance.