First Grow - Wedding Cake Auto

Starting my first indoor grow with some proper (beginner) equipment. Using a 1.5L pot (0.33 gallon) as I'm aiming to keep the plant small. I have no plans for nutrition yet, but I'm open to any suggestions. I mixed pumice into the top layer of the soil to fight fungus gnats coming from other plants, however I have ordered BTI (Bacillus thuringiensis israelensis) which I will mix with the water once it arrives. In the first days I'm using a smaller 18W lamp, as my first seedling died while only using around 10% (~10W) strength of the ViparSpectre at 70cm (27.5") height from soil. I will work towards a 18/6 light cycle, while in the first days I'm aiming for 12-14 hours a day. Day 3 update: Today I used the ViparSpectra P1000 at 10% (~10W), height 70cm, lightcycle 18/6, noticed the plant hasn't grown as fast as earlier seedlings, and it's growing taller instead of wider. Tomorrow I'm moving to 25% (~25W) and see how that goes as I'm trying to not kill the plant this time :) Day 5 update: 18/6 at 35% (~35W) today. I'm moving up the light ~5W per day to see how far I can push it. Seeing real growth in the leaves now and the plant is not growing so much in length anymore (5mm today, as opposed to 2cm per day before). Day 6 update: 18/6 at 40% (~40W) today. The leaves grew larger but the plant did not grow in length (maybe 1-2mm), hence holding off with increasing the light intensity for a day. I've added a bowl of water to the tent as to increase the humidity.