I am thinking to buy a second Slimline for this set up but I need to know that if I decide to set up my big aquarium with Lightbar II in the feature I will be able to dim Slimline from Profilux 3ex and Lightbar II from Expansion box I (or vice versa) with PLM-RS232 Interface installed in the Expansion Box.

If I will not be able to do so, it will be better to return the Slimline pay the difference in price (+ shipping cost back to GHL) and upgrade to Lightbar II (if I will have to stick with one of the two system's, Ι would prefer the premium one).