Nute burn or deficiency?

Week 8 flower still got a good 20 days to go my ph meter broke i cant tell if its burn ph fluctuations or deficiency i mean i want to flush for my harvest but Idk if i should feed another week then flush or just flush now and harvest day 75 like i plan or go extra week

Looks like a little burn to me, you could flush once real good and then resume feeding as normal.

I see no issues but you should be following instructions on your nutrient system, likely calling for the reduction of your feeding.
If you follow these guidelines there is no reason to use plain water anymore than usual, maybe reason to use less nutrients though?

could be potassium deficiency, it can look like nute burn - you will know if the leaves get worse

Thanks guys im flushing next 2 days if it gets worse il know its a deficiency and they still need some extra time i like ripe flushed buds any ways lol

Looks a little nute burn. Don't flush, it's not a toilet. Just keep watering as normal with no food.