Help please. Whats this?

Hey,

My plant was growing so happy.
She is under 400hps, and i switched to 12/12 2 days ago.

New growth is starting to put pale green, or light green. And lower leafes are like the one in the pic.

Today i gave her some nutes. Flowering nutes and Nitrogen.

What can it be?

iron and / or zinc def.. anything with potassium will fix that.. make a kelp tea. use kelp meal not liquid kelp. also a foliar with kelp

ok,

i gave her today nutes (Phoenix) that have Nitrogen 5%, Fosforus 3% and POTASIUM 13.5%
So, i should fix the problem within a week...

The nutes i have are solid if you leave them in the soil, but i prefer to put them in water, it has fast effects.

The strange thing is that i gave her solid nutes (phoenix, same as today) 3 weeks ago... Could it run off Potasium so quickly?

yes. watering in nutes, you are force feeding the plant. the plants take those up right away and when to water again those nutes are gone. if you top dress dry nutes, you only have to add nutes 1-3 times during the whole grow.. I do living soil. so all my nutes are in the soil and the plant feeds when it wants and what it wants. for veg nutrient teas with kelp meal, alfalfa meal, and aloe vera is best thing. triacontanol in alfalfa meal speeds up vegative growth plus plenty of nitrogen. kelp has everything except magnesium.. selenium in aloe vera speeds up growth too. plus tons of other compounds.