Couple of questions for you.....
how big is your air pump and air stone? It looks like your roots aren't getting enough oxygen, but I want to rule that OUT before doing anything else.
You do look like you have a bit of nute burn. Do you know PPM your solution is at?
Are you using RO water, tap water, etc?
If it's RO water it's the cause of your Cal/Mag def. and you do need to pick up some cal/mag.
You also need to use your nutrients properly. I have never used the 3 part myself, I always been a Sensi 2 part kinda guy. I DO Believe though with the 3 part you do use all 3 all of the time unlike the GH 3 part. I know it's odd and I've never believed in it so I don't use it. I'm about 90% sure that you don't use them in equal parts though.
During veg the amount of Bloom is much lower than Grow and as you get closer to flowering you start to up the Bloom more and more and lower the Grow. So if you have them in there equal then you like DO have a deficiency of nitrogen while at the same time some toxicity and burning. In order to get enough N to make your plants happy you'd have to up the strength too high and consequently burn the plants.
Best of luck to you, might consider just switching to the Sensi 2 part as it's their bread and butter and it works well.
Here is a link to Advanced Nutrients Calculator to help you out. I can't find one that includes veg for some reason, but I only looked for a minute and it's just a link directly to their calculator.
Without knowing your PPM or EC it's very difficult to be succesful growing in hydro, so please advise what your currrent PPM or EC levels are