Stable pH is more important that trying to correct a pH to natural conditions. Guppies should do fine at a pH of 8. As long as it is going to be 8 everytime you do a water change, you should be just fine.
Mines the same as yours and therye fine DOnt get any plecos though as theyre real sensitive and they need a pH between 6-7.5 (made a big mistake buying an exspensive plec with it dying within 2 days and only getting 50% refund as it was my own fault...with the pH being too high )