Hi,
So the only things I could suggest would be to water with ph a bit lower, maybe 6.4-6.7 but checking your runoff like mentioned will help to know the outgoing, if its low ph then its being buffered. And with the flora nutrients, if you can give them the grow, bloom and micro for the next few weeks that's preferable to only 1 grow or bloom. It may be that it's needing a bit more nitrogen.
See if the yellows leaves pull off easily..if so, most likely a N deficiency.
Happy flowering. ✌️