I have 3 other plants growing in the same hydro set up, and they show no signs of this, and only running 1/4 strength of nutes. these are the bottom leaves. the tops and middle leaves look great. plants are about 8'' high. do you still think it over feeding?Looks like the onset of obesity.
Classic overferting.
HTH
PH is 6.0 and no chance of splashing any nutes on them. Thanks to all the replies as They look great other than this, like you say I won't worry anymore!If the rest of the plant is ok, its looks like you could lose that fan. Did you by chance get your feeding solution on the plant while feeding ???? If all the rest are healthy i wouldn't sweat it to bad