Just curious, but how can you really say pH is perfect? You have peacocks/mbuna which like hard/alkaline water, a Texas which likes soft-slightly hard/acidic-neutral water, and cory cats which like soft/acidic water. There's literally no way possible to have a perfect water chemistry for the group of fish you chose. And as Old Newbie mentioned, that's a group that most likely isn't going to work out together. It's generally not recommended to keep any mbuna in with peacocks, because mbuna as a whole are generally way more aggressive than peacocks. The mbuna you chose are Kenyi, which is among the most aggressive mbuna species out there. They're so aggressive that most of the time they can't even be kept with a lot of other mbuna species, so they definitely shouldn't be kept with peacocks. And as far as the Texas goes, it's most likely either going to be killed young by the Kenyis, or it'll make it to adulthood and get so large that it'll kill everything else in the tank. Overall, I'd say you need to choose which fish you like best and swap out the others for better tankmates. Probably shouldn't keep the Texas at all unless you're willing to upgrade to a larger tank in roughly a year. Keep the peacocks and make it a peacock/hap tank. Keep the Kenyi and make it a mbuna tank. Or keep the Corys and make it a community tank. But keeping them all together will most likely lead to disaster down the road.