|10-ish, I guess?
Do make sure you’re using a good feta — I bought a brand I don’t usually get this time and it’s so salty I almost can’t taste anything else.
Also, lime juice really is the best citrus flavor for this. Orange is too sweet, and lemon and grapefruit are too sour. That said, if you don’t have lime on hand, use lemon or grapefruit and cut the amount by half(ish).