2 of my plants have yellow/brown spots developing on leaves what's going on?

[Dankbuddy]

i'm currently growing 11 plants that are about 4-5 weeks into flowering. in the past couple days i have noticed that 2 of my plants have many drooping leaves and quite a few leaves are developing yellow spots on them that progress to brown and grow in size. the other 9 plants seem fine as can be. i have them in 5 gallon soil buckets and am supplying pro bloom, hydroplex, sweet, and liquid karma at full strength now that the plants have grown to 7 or so feet. this is my first grow so i took my friends advice and stopped using calmag soon after switching to 12/12. can that be a problem? as far as lighting i have a 1000w and 400w hps but plan on upgrading to another 1kw for my second try. im thinking of trying SOG but dont know exactly what strain would work best. are there any forums that are SOG oriented?

2 of my plants have yellow/brown spots developing on leaves what's going on?

[KittensOnPCP]

Yellow/Brown spots can be from a nutrient overdose, i'd clip the spots off so they don't spread. And being droopy could be from over-watering or under-watering. BTW - 7 foot plants, holy shit. Oh, and I think it's 22,000 lumens is max per plant, so depending on your lumen output, that extra light shouldn't be needed. No SOG forums, but there are threads about it here, just do a search.