Hey guys first time grower need help

i have moved this plant to the flowering room which sits about 24 to 28 degrees celsius, it is under a 400 hps bulb (about a 12- 16 inches higher than top of plant) 12 hr cycles. I've been using Guinness nutrient formulas (micro, bloom and gro), with distilled water, to the recommendations on the bottles for flowering stage, I had no problems in the veg stage of this plant using the label on the back. Now I'm not sure if I'm overwatering or if it is infact nute burn itself. I've backed off everything (watering and nutrients) as well as added an air stone to the water mixture. I'm looking for some seasoned growers to give me some opinions and advice as what to do. I was also wondering if I should put it back in veg till it gets healthy and strong again, or if this would cause to much stress.

No dont put it back in veg its too lanky already. Temps are too warm. Also what is ph? ppm? and are you cleaning the res every 2 weeks scrubbing it out?.

ya did good backing off. is that hydro, or just some medium on top of soil?

its hydroton, ph is around 7 and the ppm is 980, and i am swapping out every 2 weeks.

update i also added ventilation one bring in (cool) and one pushing out (hot) air to drop the temp of the room

have you tried lowering ur ph? ph @ 7 seems kinda high in hydro i stay around 5.5- 6

can i use lemon juice to lower the ph of the water or will this hurt the plant in anyway?

i was also wondering about using baking soda to raise ph levels?

Baking soda adds salts..not so good. pH up and down are better. Hydro pH should be lower.