Have a look please

One of 3 plants grown from bagseed is showing small symptoms of don't know what. i'm not too concerned as the plants is quite healthy in general and growibg fast. They're less than a week from flowering. The edges of the leaves are plae yellowish and certain fan leaves have small orange/yellow dots on them. I've got a couple of pics for you, not the best quality but you should get the picture. Any and all advice welcome.

With out more info such as medium, feed, and etc.. it's kind of hard but from what I seen it could be splash burns from feeding and water or feed getting on the leaves. Possibly very early cal/mag.

I'm using your average sterilized potplants soil and feeding with HESI's nutrient schedules and products for soil, according to recommendation. Are you saying too much or too little Cal/Mag?

yup either splash burn or water burn always feed them at lights out to avoid splash or water burn. but yeah could be early stage of cal/mag def

Also, gow room isn't fully sealed and humidity levels have not been monitored so far. Temp. Is fine though 25 degrees celsius. The 400w HPS has a cooltube. There is no exhaust fan(just a a basic cheap one) and the floor isn't covered with a reflective surface. Those are all the factors I can think of.