Awe, that's a moerse pot bru. Can I suggest staggering your pot size. Start off small, like in a solo cup, then bump it up as required.
As for nutes. Seeing as you're going organic, look at biobizz. I use it. My tap waters pH is around 9, the grow and bloom mix drops it to around 6.0-5.7. I haven't used my pH pen since I noticed the numbers during veg and i'm harvesting next week.