If you’re doing an organic, water only grow, you shouldn’t have to pH anything. As long as it’s between 4.0-8.0, you should be fine. I do make a habit of checking anyway so I know and I only adjust if it’s too high or low. I have a chlorine/chloramine filter on my tap that brings my pH up to around 8.0. In that case I’ll adjust it to bring down somewhere between 6.0-7.0.
Important things to note:
1. Make sure to use chlorine/chloramine free water as those will kill the micro life.
2. Should you adjust the pH of your water, do NOT use any chemical Up or Down as that will also kill the micro life. Baking soda is good to use for pH up. Citric acid, lemon juice or vinegar will drop the pH down. I like citric acid as it’s super cheap and works great. Be careful, a tiny pinch will drop the pH significantly.
3. Do NOT water until runoff. With an organic grow, all of your nutrients are in the soil. If you water til runoff, you’re just washing away nutrients and micro life.