Don't worry about the height. It's usually a genetic thing. Personally, I prefer short tight plants early on, since they usually stretch out during flowering. If for whatever reason you needed to induce stretching, you could either raise the lights or feed it more nitrogen. However, nitrogen can also burn (and kill) your plants and moving the lights to far away can do more harm then good. So that's why I just leave them alone.
When it comes to PH, I only worry about it if I'm using cannabis specific nutrients or specifically, hydroponic-style nutrients like General Hydroponics, Advanced Nutrients, etc. If however you decide to go the organic route (NOT organically derived but designed for hydroponics) meaning: compost, mulch, manure, and meals; then you don't really have to think about PH and your 8.5 ph tap water is just fine. True organics are slow releasing and have natural buffers which limit the possibility of over-fertilization.
Also, I really don't like Fox Farm Ocean Forest for starting seeds. Others might have difference experiences with it, but whenever I use it I notice burning and stunting. Instead, I like to hold off on the Ocean Forest and start with a seed starting mix like Miracle-Gro Seed Starting or Fox Farm Light Warrior. Then after a month when I'm ready to transplant into a larger container then I'll move to a full strength potting medium like Ocean Forest.
Lastly, don't expect the impossible. Autos are short. Usually around 1.5 ft to 2ft. even when grown outside. The trick is to grow a lot of them. And just like the plants at Home Depot or Lowes, some will die or have weird problems. You shouldn't really have to do a lot to an auto since they are so small and flower so quickly. Most common problems with autos is to strong of soil early on, over fertilization, weak lighting, and hot grow rooms.