magnesium defficiency??

hey ppl has anyone out there had magnesium def where the leavesyellow then brown and curl??
ive sorted my prob out i was just wandering if anyone else has had it during veg and whether the yields where effected by it??? ppl??

i had a mag deficiency during flowering not veg. i bought a product called cal-mag from botanicar for 20$ a quart and used it every watering as per instructions and everything went back to normal in about two weeks.i think yeild may have been affected slighty,i couldnt tell becuz the buds were still fat and dank.

thats reassuring cheers man i used dolomite lime water got mag and cal supposidly and nuetral ph