My seedlings have died after almost 2 weeks. Just 2 days ago, they were looking fairly healthy, I left them alone, without water for one day (I'd read that leaving a day w/o water helps roots grow - searching for water), and today they are completely dead (completely wilted, most leaves look dead). It looks to me like I'll be restarting, but this time I want to give my exact setup online here, get specific advice, and do what it takes to make sure nothing can go wrong. I'm sure they simply needed water and didn't get enough, but it also might have been a nutrient problem (one leaf was just starting to get a yellow tip just before this happened), or even a CO2/air circulation problem for all I know (I'm not a gardener, this is my first grow).
I am growing in a closet, 2 plants (ministry carnival) under my 1'x2' florescent lamp. I have a 4" duct fan pulling air through some air filters and out of the closet 24/7, it is rated at 80CPM i think, but seems a bit wimpy since it's pulling the air through 2 carbon filters and 1 electrostatic filter and then down a long tube and out.
I had one 1'x2' floro lamp which is 10,000lum (6500k) hanging about 12" above my plants (probably too far away now that I think about it). I was using a 18/6 light cycle. The light seal around my closet is pretty okay, but I did have my room's light on somewhat often when they were in "night"; perhaps the night should be more perfectly dark than that ...i wouldn't know.
I used Miracle Grow Organic Potting Soil mixed with a little perlite. I figured this soil would have the nutrients I'd need through the veg phase and would be at a reasonable Ph. I did notice that one of the leaves on one of the plants was just starting to turn yellow at the tip the last time I saw them healthy. Also, my larger, step-up sized containers for the seedlings to move to, are slightly over 1 gallon, are these two small? If I plan to switch to flowering as soon as they get to 18-20", what sized containers should I be using? How many plants will fit under my 1'x2' lamp?
I'm somewhat confident this was simply a problem of underwatering at a crucial point, but it could have been anything. Could I please get some concrete advise about watering amount and frequency? A lot of the advice i'd read online said, essentially, "Don't water every day; wait until the surface is crusty dry before watering again". This confused me though since the soil would be crusty dry again just 4-5 hours after watering! I mostly would water once a day, in the afternoon sometime, and skipped a few days as per some clearly problematic advice. Should I just be getting the surface wet when I water, or should the entire volume be soaked through at each watering?
Please tell me what I need to be doing to make sure I don't kill my plants again! I can be relentless with following your instructions, but I am completely new at this.. so I probably shouldn't be winging it.