It was definitely over watering that killed em.... 2gal of soil for such a small plant would have worked had you not watered them so much.... Like bigsby mentioned, about half a small dixie cup would be enough moisture to last a couple days or so for a rooting seedling....

What you need to understand about roots in soil - Roots want to stretch and find the very last bit of moisture in the soil.... If you make it too easy for them, i.e. over-watering them, the roots simply give up.... However you don't want to let the soil dry to the point of stress either.... Practice is the only way to find how much, for how long, works....

So you going to give it another go??? You mentioned too much light.... What size lamps you working with??? And how close were they???

CGI::::::