First grow AK-47 Autofower

If there's good runoff, it won't waterlog if you are adhereing to a good wet/dry cycle and not using a pot too large for the plant. no worries. A plant may droop slightly after watering.. it'll perk up in no time when sticking to that cycle. if pot is too large, only water in an increasing radius over time. Does not seem to be the case neccessarily from pictures, though. A slurry is going to give a more accurate idea of soil pH. Understand that it only tells you the direction the pH lies and less so about exactl what it is beond general idea of how large of a gap it could be between input and output water pH. So, without destroying too many roots, take a sample a few inches down near sam leve where rootball is likely to be. pH the water before you do this... create a slurry with teh sample, then take pH again... if it is drastically lower, you know it's quite a bit more acidic than the water you put in.. etc.. greater the difference the bigger the gap, but expect it to be further in whatever direction it goes from initial measurement of water used. it's inexact, but useful information. You can do the same with runoff too... from what i know a slurry can be more accurate. try to use as much soil as possible relative to volume of water that still allows your pH meter to work well.

To measure the ph. from the ground there are simple tests which are not expensive and avoid flooding (the good old measure as in college 20 years ago 😉) but it would still be necessary to check the ec .... Compared to the watering, each genetics is different, personally I weigh the pot and monitor the leaves. To avoid root rot, use enzymes 😉