I know that taking pots isn't optimal. That's why I said an Amplifying Tome and a mana potion because if you use your Q to farm, it can get kinda mana-intensive. For beginners who aren't used to using the passive is why I suggested the health potion route. Maybe I should elaborate that on my guide.

i have no idea why there are already two downvotes and no one explains anything.

Anyways I havent voted yet but this is my opinion. Ahri doesn't really need hp pots simply because of her passive Soul Eater allowing her to sustain in lane for quite some time. You shouldn't be taking too much damage as Ahri can last hit from a safe distance and if the enemy approaches you, you should be moving around a bit. Simply put it, you should be able to heal more or equal to the amount of damage you receive. It's just an issue of preference. I've seen a few Ahri player take pots and played succesfully but I just dont take pots. Instead I take a Doran's Ring for mp regen, hp and some ap.

I also agree that I would probs take Greater Glyph of Scaling Ability Power instead. The fact that you take Greater Glyph of Scaling Magic Resist and said in the mastery section about the defence tree kind of contradicts each other. So could be a bit confusing for someone who is new to the game to read.