Yellow / orange zones on leaves ?

70% is way too high for flowering. 30-50% range is ideal. PH is at the low end of the spectrum, and wouldn't hurt to come up by .2-.3 temp might be a bit high for flowering as well, ideally 19-22. Feeding K helps bloom yield, but should impact leaves. Normally at tend of flowing the leaves start to look like you sucked the color our of them from the main stem with a syringe, and the spotty yellow isn't ideal, but probably isn't a huge issue, and is more likely cause by too much nutrients than too little and spotting and tip browning can be symptoms of root burn.