I had a pair of bolivian rams and apistogramma caratuoides in a Ph of 8.0 for a year. Just moved the apistogramma to a tank in another location with a lower Ph of 7.6. All fish healthy and the rams spawn regularly. It may be that the higher Ph is not promoting breeding for the apistos but they are active healthy fish otherwise. I think of both of these are pretty hardy. They are tank bred, not wild so usually that means they can tolerate a wider range of Ph. Remember with Ph, stable is more important. I had the two pairs in a 48 inch tank and there was a bit of chasing but they did fine. Two pairs in your tank might be pushing it but if you limited the bottom fish and had lots of hiding places and good filtration it is possible. These fish, in my limited experience, occupy the bottom 1/3 of the tank.