Changing is only bad when you change to the wrong thing, or combination of things. Besides the small ph up drift, how are the ladies looking? Can you pre-lower the ph a tad and maybe itll bounce within a lower, more acceptable range? Personally, I like to finish out the nutes I buy, before trying new. That and Ive also noticed that among the top nute manufacturers, its perhaps more about fine tuning what you got, rather than chase labels. Soon I'll give another label a go, as a side by side, but scares me to relearn a nute schedule mid grow. Just my 2cents. Hope you find the perfect blend! keep us posted