@14she, sounds good. I wouldn’t worry about it then. They can grow up to 48” or so and is still perfectly normal. You may also try lowering your light to around 12”.
I would suggest you add a calcium-magnesium supplement or (cal-mag) to your next feeding. It looks like your plants are in slight distress due to a deficiency. Usually this is caused by bad ph or overwatering, but it doesnt look like you did either, so my guess is your nutes are just lacking it and you should add some to your grow.
Personally I think you should be fine with 600w, what spectrum of LED is your light. Typically blue is for veg, red is for flowering, or you can use a full spectrum throughout the entire grow.
14she
