As your ppms get higher it should be easier to stablilize because there are usually buffers in the nutrients mixes to keep ph stable. Lots of nutes....more stability.. Sometimes tap water can be hard to stablize ph as well depending upon whats in it....don't know if you are using reg tap water but if it has stabilized that's neither here nor there at this point.

When I start to worry about my ph is when it starts rising very quickly without an obvious reason....as it certainly can suggest things like heat stress, overnuting etc etc and I like to find out why....hopefully before the plant crashes down around my ears. Nute burn is the most common one that raises ph like that imo.

The more you grow the more you will take notice of things that don't seem normal and be able to use that info to your advantage. Practice....

Wow, I'm still impressed about Doco...