So I have one plant that has some yellowing tips (see pic below). It's a GDP clone. I transplanted it to the one gallon pot 2 weeks ago along with some other clones that are doing fine (so far). The soil is Roots 707

I have all of the clones under LED (18/6), the room is fairly warm-about 85-90 with about 65-70% humidity. I am feeding them a mix of Pro Blend Grow, along with cal/mag, vitamino and liquid karma. I have reduced the recommended dosage of each because I am blending them together. I am using tap water that sits for a few days to outgas and then after adding the nutes, correct the PH to 5.5. So am I seeing nute overdose? If so, would flushing with PH'd water correct the problem?

It also has some leaf curling occurring on a lower leaf (see pic below).