How to fix Overwatered or under watered?

big pot, little plant. dont fertilize first 10-14 days. after that wait for cotyledons to fade a bit and start slowly, and increase concentration over time. water in small radius around the seedling. 3-4" or so, and make sure it gets soem runoff.. you need to get that column at the least wet.. a little more is better than a little less. Also, don't let outer area get bone-dry during this process... it doesn't have to get saturated but hydrating it a bit will help avoid repelling water later, which is very difficult to re-wet. increase radius with growth of canooy. it's not too oversized, so withing 2 weeks you'll be watering entire pot i'm sure. e.g. your other 2 plants you canprobably water whole pot no problem and be safe. allow top 1" to dry before irrigating again.. feel weight of dry and wet pot.. learn that weight difference. you may be able to keep a really consistent schedule early on, but at some point if not feeling weight, you will wake up to a slightly wilted plant.