I’ve had the same thing happen, except my flower lights are Blackstar 180w... I’m new, so I thought I’d probably made mistakes, but it seemed odd that things went wrong within days of changing lights.

The same thing has happened on my new grow. However, I have some plants grown from seed and some from clones under the same lights. The clones are yellowing, but the seed plants are fine! In fact, I have one seed plant and one clone in the same pot, showing different results. I wonder if clones are less hardy. I've tried all the iron /magnesium /sulphur deficiency stuff.

Please keep posting your findings, I would really like to get this sorted.