don't need to trim - unless you want to do so. As long as internode space isn't long or stacked on top of each other, your light is fine too.
Looks like a deficiency, but need more info.
e.g. if it is soil and you've fertilized from day 1, it's more likely lockout, so you'll need to consider recent behaviour.
do you water only after top 1" dries? do you always get 20% runoff or more? These things maintain equillibrium in the soil so it doens't build up too much and you don't have a dry pocket of substrate or some region of your substrate with inconsistnet nutrient levels that can becomes real problems in short order.
Also, 7 is probably a bit higher. Get it to 6.5-6.8 for soil.. at least slightly acidic.. don't have to be as precise about it with soil. I'd try that along with any changes to watering habits i mention above and see how it reacts.
Also, start calculating the PPMs of the feed you put in -- this will help diagnose problems immensely! Nute ppm calculators exist on the web.. you can also download my spreadsheet linked in my GD profile comment senction. It may or may not work for liquid nutes, so verify with an online calculater with at least one of your guaranteed labels, if you choose to go that route... belive it handles specific gravity correctly, but i do not havea a degree in chemistry.