Wilt To Live

So long and short I changed the water in the RainForest 36 today. My sweet peas are shooting up, however three of the four spinach seedlings are wilting. The starter leaves (I know there is a word for the di something that sounds like a dinosaur) started to wilt followed by the true leaves. I'm not sure if there was too little light? Or the roots never got a good start. Going to try to start my next seeds in Sure To Grow cubes.