I would like to set up my 75 gal tank for Lake Tanganyika Species. I have been looking at you tube videos and researching for the last few weeks. I would like to have 1-2 species that are either sand or shell dwellers, and 1-2 species that occupy the middle level of the water column. The pH of my water is 7.4 , the Gh is 180 ppm and Kh is 90 ppm. Any stocking recommendations will be greatly appreciated.