PH - soil is around 5.5 - 6.0. Water has been around 7.2 - 7.5.
Not sure if anyone pointed this out, but 7.2-7.5 is way too high for your input pH.
You should be going in at 6.3-6.5 in soil.
I've used Black Gold before in my (bloom) soil mixes. It runs alittle hot, so you probably would have been okay without feeding for at least two weeks after sprout.
With auto strains, you typically want to start off in your final pots.
My recommendation… run 2 gallons or so of fresh water ph'd to 6.5 through each plant, then get them into your 3-5 gallon pots. Saturate the soil and let dry completely before you water again. If you're using the same soil, don't feed for a couple of weeks. If you are having trouble finding decent soil, just grab a bag of Miracle Grow Organics from the store. I know people say it's no good, but I've used it plenty of times without any issues. I add in a bag (8 qts.) of perlite to a big bag of MGO to help with drainage, and have a solid wet/dry cycle.
I'm not familiar with your nute line, but I recommend getting something made for cannabis. Mega Crop is super simple to use and cheap.
Also... read the How to properly water... link in my signature.