Potential Magnesium Deficiency?

Hey guys, I just got three clones from a friend and I think they all have a mag/worse deficiencie going on. They are about 3 weeks into veg and are in 500 ml pots which mystifies me as to how they haven't got more deficiencies yet!. My set up is a 600w hps light in a 1.2x1.2x2 meter tent with an intake fan and an extractor fan and currently running 18/6 light cycle. btw the nutes I am using are canna terra vega. Any help would be really appreciated, will attach photos.

got any pix of the new growth? that would help too

it could be phos deff, but wait for a few more opinions first.

what are you feeding it and ow offten?

Yeah mate cheers for the response, this is the best I can do for now

I have only had the chance to feed them once and since there in such small containers I didnt want to overdo it so I fed them with canna terra vega at 0.8 ec with the ph at 5.9. The runoff for two of the ones that I checked were 5.9:0.8 ec and 5.9:1 ec

Doesn't look like magnesium deficiency. What medium are they in?

Looks to me like it's time for bigger pots..

Cheers for the response, Someone on another thread has suggested a phosphorus deff?. All my friend knows is that there in soil and perlite. Was going to repot them today into 4 gal pots with canna terra professional medium