Durban Poison Auto 1st Grow

First 2 days was still in Veg then on 3rd day it started to Flower. I was hoping to get a full 4 weeks of veg but with Autos they do what they do. Had a bit of over watering again. She had some yellowing in older lower leaves from it. Then brown spots began to show on a few leaves, so I turned offside lighting and reduced lighting to 700ppfd hoping it was light burn. But it wasn't it was Lock Out and she wasn't growing any more. Got some great advice from folks and decided to Flush and reset my medium. I don't have Meters, so I wasn't sure if its high or low PH issues. Flushed 4 gallons of water through the medium and allowed the runoff to escape and wash away salts and build up. I believe this issue is because I rarely allowed my waterings to cause run off. That allows nutrients to sit in the medium too long and become too high ph. By the end of the week, I got my meters and confirmed my ph levels. Tested my tap water with Honey and B-Vitamins and it's 9.8ph. Water alone was 9ph. Way too high for cannabis. Ordered some PH Down and will use that to control ph levels. After flush she looked a lot better took soil samples and soil ph was 6.3. Did some LST a little at time to not cause too much stress (Tucked leaves to open up bud sites, and lollipop lower 1/3 of plant). Got rid of lower bud growth sites that would not produce so the plant can focus its resources on exposed top Bud sites. She has some scaring but is currently healthy. Gotta get that PH Down soon or I'm going to have problems again.