First-Ever Indoor Autoflower Grow

As of the morning of April 29th, the plants have received their first watering/feeding. I was gifted some sample packs of Elite nutrients by one of the owners of my local hydro store and will see how they do. The water used was rain water that was collected and filtered from the storms of the last couple days. As of the evening of April 30th, I watered plants in the late afternoon with plain water ph'ed to 6.3. The plants range in size between 1.75” tall (Industrial Plant Autoflowering CBD by Dinafem) to 2.5” tall (Seedsman White Widow Auto). I misread my feeding numbers I had written down when trying to convert ml to tsp and accidentally gave too much to them on the first feed! They look healthy but today I gave them regular water just to be safe. I decided to move the lights from 18” away to 26” away. The temperature in the tent is staying around 73F and the humidity is staying around 40%. As of the afternoon of May 3rd, I added a pot of water to try and bump the humidity levels in the tent up a little bit to something more consistent. I've been having humidity in the tent fluctuate between 27%-41% throughout the past few days and I don't know if I should be concerned? As of the evening of May 4th, Industrial Plant is on Day 13 and all other plants are on Day 12. Mephisto Genetics Ripley's OG is 2.5” tall, Seedsman White Widow is 2.5” tall, Dinafem Critical Jack is 2.25” tall, and Dinafem Industrial Plant CBD is 2.25” tall. The stems on all 4 plants have definitely gotten thicker and the leaf growth is really taking off! They'll probably need their next water & feed here in a couple of days at the beginning of Week 3. As of the evening of May 5th, both the Marshydro Mars II 1200 and the ViparSpectra Reflector Series 600 LED lights are running in the tent; with a combined true wattage of approximately 790 watts. A new hygrometer was purchased because my old one died. I went ahead and updated the new temperature and humidity readings in the tent.