well youre using a 1 part bloom mix, you should be using their grow. Flora Nova is used when flowering. If you want to stick with General Hydroponics then go pick up their 3 part nutrient system, 1 bottle of floragrow, 1 bottle of flora micro and 1 bottle of flora bloom. Ask for a mix chart if it doesnt come with one.
There are buffers in the nutes that help keep you PH stable. But first you have to be using the correct nutes.
If you want somthing a bit easier, with a better recipe, Id go with Dutch Master Gold, there is a 2 part mix, A & B for Veg, as well as a 2 Part A & B for Flower.