24k gold

This is a 24k gold plant in dwc hydroponics. I was planning on changing it to flower light, 12/12 next week. Brown spots began showing up on my leaves. The tips of some leaves and looking a little yellow. Any tips or advice on what this could be and how to resolve my problem

It almost looks Rust disease which is caused by a fungal parasite that needs living plants to survive. Did it start underneath the leaves?

Did you get the bottom of it? I'm having the same issue