Welcome to our forum, thanks for sharing your tank with us.
pikkio, your system sounds like it is designed just fine so far. Any pics you could post would help greatly. Don't worry about your English, we communicate just fine in here when it comes to reeftalk.
When trying to second guess future problems with your nano, there's really only one thing to be concerned about--lack of proper maintenance. When you change water, make sure to stir up the tank every once in a while to blow out all the crud that builds up between the rocks and the sand. This idea works well with larger-grained substrates and less well on finer-grained substrates. They key is to not let your nano store up wastes that strain the system over the long-term.
Also, I recommend not adding a whole bunch of items to your nano, the things we most commonly advocate in this forum are: Calcium/Alkalinity additives, frozen foods/pellet/flake marine foods and phytoplankton supplements. We do not recommend adding trace element supports, wide-spectrum supplements etc. Also, keep your fish stocking to a bare minimum-- fish are very taxing to nanos and make regular maintenance all the more important.
Good luck, keep us posted
