New Growth is Bright Yellow Leaves, pics

I have 10 White Queens at 4 weeks and on 1 of them the new growth is bright yellow, the other 9 are perfectly normal.
The only thing I can find is a Sulfer deficiency and to use epson salts to fix it??
All 10 plants were sprouted together with the same potting mix and nutes.
If anyone says Nitrogen deficiency, well It's not so dont bother.
Soil is
40% Premium potting mix
30% Worm castings and
30% Perlite
I've only included 1 other plant for comparison as they are all virtually identical.
Oh, they were repotted last weekend into 1 gal pots from 1/4 gal pots but they weren't rootbound yet.
Thanks.

These are in a cupboard 5' x 3' and 5' high.
2x 200W envirolites and 1x 400W HPS with oscillating 12" fan and good ventilation.
I have though of lioght bleaching but I keep this one on the outer edge so it's only getting the 200W 6400K light on it.

So no one has a clue
Where are all the experts that insist they know everything

Hi spiker1, im not an expert but my opinion is :

Sulfur def.

Sulfur: Young leaves turn pale green, while the older leaves remain green; plant is stunted and spindly...


Could be ?

id try useing a teaspoon of epsom salt with a gallon of water , this should cure your issue. good luck

Thanks for the replies, I bought some epson salts and will try it tonight,
just strange why it only happened to 1 plant.