I noticed a bronze spot on a leaf?

So I was doing a water feed today and as I was waterin I noticed the plant had a bronze spot? As far as nutes I'm using Dr.Earth Nitro Big, Dr. Earth Golden Bloom, and Botanicare Cal-Mag Plus. I do te feed every other watering but I notice these spots wouldn't it be a mg defiency? Am I using too much cal mag or not enough? I use 3Ml per gallon along the other nutes. After I use a Ph meter and adjust ph level using Ph up & Ph down. Lighting I'm using 1000w hps air cooled hood. Temp is somewhat high not really. Any help would be appreciated please.

Whatever it is, is insignificant, probably. I get all kind of weird colors and growths and holes chewed (on outside plants), and yellowing here and there and distorted growth, and a lot of other blemishes that are like acne on a teenager. In the long run they are nothing. Step back and look at your plant from 6-8 feet away and if it is generally green and growing big healthy leaves...... thats all you can hope for.