But, they don't look overfed to me.

It's a LOT easier to help if you give folks an outline of what's been going on. Media, feed, environmental parameters, etc.

^^^ what she said....it looks more like ph to me but idk all your details

Looks like an lighting issue from what I see,but need more info

Your plants look like a few things are wrong:

-I'd recommend flushing the medium thoroughly with a flushing agent (Use twice the volume of water as you'd normally water with, to really get those salts out)

-Make sure you're not over watering; let your medium become somewhat dry before watering again (You can stick your finger into the soil up to your second knuckle and feel for moisture, or you can pick up the planter and gauge by weight)

-Ensure you're using a proper light to grow with and make sure it's close enough to the plant; no regular light bulbs (Your internode spacing is pretty far apart, indicating stretching for light, also your leaves look pretty skinny and i doubt it's related to genetics)

-Try using a really good soil mix next grow. Buy a bag of premium soil from a major company in the industry such as: Roots Organic, Premier, FoxFarm, BioBizz, Sanctuary....try to avoid cheaper soils such as miracle grow.

-Look into earthworm casting teas, they can help in many ways

Hope this helps bud! Just keep on growing and asking questions and you'll be growing great plants in no time.

Need more specs.

I mean I've never gavd it fertz before and now look at it, the one im using is 20-10-20