Well Bulster I'm no expert, but i think you have a combination of problems here..

You can obviously see the fert burn, but also some kind of nutrient deficency is present, possibly N, because of the yellowing, but that could be because of some lock-up thats going on (although I wouldn't want to advise on what tho).. You're adding PH adjusted water, but have you tested the PH of the soil?

The soil looks a bit peat based for my liking, i'm not familiar with "Supersoil" tho. I would have added a lot more perlite.

You also say you have days over 100f, and other "cool" days - massive differences in temps will also stress the plant.

They just look generally stressed out, i'd just see how things go for a coupla weeks.

Keep us posted!:thumbsup: