The top of your plant is looking good, but the bottom is not healthy. The plant is using nutrition in the bottom of the plant to feed the new growth, indicating deficiency.
Your soil does not have much nutrition in it. Peat moss and perlite add nothing to the nutrition but the compost has some in it, but has surely been used up by now (6 weeks).
You will have to feed your plant often, Adding nutrients every time (or every other time) you water your plant. I have no experience with that trio blend chemical you are using, but others here may. Rely on that as your plants supplement, rather than the soil, follow instructions on the bottle as if you are growing hydro.