Hello
So I'm not seeing very bad tip burn on the plant...but your leaves are pretty dark green, which can be signs of an N excess. Would this plant have that same manure as the diary on your page? The spotty look makes me think a bit of calmag might be needed if that's available to you? But I'd say bring in a small flush and then come in with a low dose of nutrients. If calmag isn't an option..i know ca is best absorbed around 6.2, but if you're between 6.2-6.5 it should pick it up if available. Some plants are extra hungry for some nutrients though and not other nutrients.
There's also the fact that many plants will have lower leaves yellow and die off as flowering continues...so maybe pay attention to how many leaves are showing this symptom.