Humidity is way too low, shoot for 65%-70%. That will help the leaves from drying up. The plants are way young. Flush with PH correct water. You need a ppm of ~130-150 before adding any ph buffer. To be simple, buy some distilled water. Add Cal Mag+ to that water until the ppm is 140. The ph will be 5.8. Add Fox Farm Sledge Hammer. (follow the instructions for Sledge Hammer and use it as often as it recommends to avoid build up) Check ph. You shouldn't have to buffer. Flush the media with this solution. Take the ppm of the runoff. It will probably be super high. Ocean Forest is the most augmented soil Fox Farm makes, you have small plants that aren't taking on that additional nutrients you are giving. The soil has a really high PPM to start with, it just needs water for the first few weeks or so. You've added so much that there is a build up, and the plants are having trouble taking on water because the water is saturated with nutrient salts. When nutrient salt concentrations go up, ph often goes down. Fox Farm recommends making a slurry of the media to get a ph of the media. However, checking the ph of your runoff is going to be useful here to see the ph of water once it dissolves the salts. When ph gets very low, the soluble nutrient salts react with acids and precipitate insoluble compounds. The insoluble compounds are conductive, ionic salts so they add to ppm--a measure of conductivity. But they are not available to the plant. They are "locked up". What needs to happen is the media needs to be flushed out completely over several days. Then, when you flush them over the next few weeks and get to a proper ph, and a reasonable ppm from your runoff, you can start adding nutrients. Ignore the amounts on the Fox Farm instructions. Go for a PPM of 200 to start, not 400+. That is add 200 to the 140 ppm of cal mag in your distilled water, so 340 ppm total with Bloom Big, and Boomerang. Use that for a week or two. Then add about 1/2 the Wholly Mackerel in the next week. The following week add the full dose. Ramp up to the 420 ppm they recommend. Now you can start with the schedule. Over the next month go on the low end for ppm on the feeding chart for veg.