First grow - DIY setup - Northern Lights

Nutrient deficiencies don't mean to stop ! Tiny brown spots appeared in some leaves. After research I think its calcium deficiency :/ After all these different strange symptoms in the last days I believe now the main issue is that solution's pH is wrong. Unfortunately I don't own a ph tester yet, although I intent to buy for my next grow, so I decided that I will go all the way with nutrients + 1 week flush and not change anything until harvest. I believe my little Sensi will make it through the end... The good news is that buds are getting bigger and bigger, although growth its relatively slow I think due to high humidity or maybe cause of all these socking conditions. Last but not least, a few of the pistils are turning amber... Harvest is not far away... Wish me luck!!!