Yellowing is a sign of over watering or generally too wet on a sprout, do you have holes in the cup? A t5 won’t dry the dirt and they look too wet, better let them dry up and get some holes if there are none. Might be why the one has some yellowing. I even put them on the side down low, helps dry it quicker. I water small guys with a spray bottle, couple sprays is good. Looks good though! Well on your way, let them dry, those cups should not have much weight to them.
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