Yellow spots on my tahoe leaves ! ! Help!

My name is ocean this is my first grow in dwc this is whats going on....started from seed now there about a month and a week old..am useing flora nova grow also some cal mag at 250ppms my total ppms are between 500 and 600... temps in room are from 75 to 80f and humid. is 40%..ph is between 5.7-6.3 useing a 600watt mh plenty of air flow 18\6 light cycle ...........now am getting these yellow spots on the leaves i dont know what it is but i dont think its a pest problem i leening more towards a cal mag problem maybe i need more? i dont know but here are some pice please help me out thanks

It looks like the start of a calcium deffeceny. I don't do hydro but I wanna say you ph might be a little to high. 5.5 -5.8 is the ph you guys normaly run. Running to high starts to lock out nutes

thanks bro will note the ph issue anyone else?

Can you tell me what these spots are?