i have a oddbal 180 gal tank its 48"x24"x36"tall. i have had tanks for 5 years or so with great luck but now i want to try discus. 1 how many discus can i put in here and keep them happy? 2 what tank mates can i look for (i have lots of plants and caves) i would like to ad some inverts if posible. 3 water specs kh=4 ph=7.6 temp=79 are these ok or do i need to adjust anything befor i buy? thanks for any input i just want to do this proper like