need advice with proper nutes feeding,please help!

I currently have a 5x 5x7grow tent I have proper fresh air intak and a charcoal filtered exhaust with a 600watt HPS bulb and balast in an aor cooled hood. I had 12 plants 6 Northern Lights 6 mystery strain I just recently switched them to bloom. I recently had a spider mite problem for the first time, after about 3 weeks of slowed growth and almost death to a few of them I finally got the problem under control,I'm still once a week spraying with organacide and I currently have a multitude of ladybugs finishing off and preventing. I haven't seen any new damage nor any signs whatsoever of the spider mites in about 3 weeks but also the damage done caused major delays in my growth and could quite possibly be the cause of going from 12 to 6 plants. I just chopped down six males and they seem to be the ones that were put under the most stress!the 6 I have left worked out pretty good because I am left with three of each strain,even though this is my fourth grow,I am still very new and using trial an error,plus this is my first grow with actual ordered seeds.my last 4 grows were with a bunch of seeds given to me by a friend and they actually turned out to be white widow and produced really good. I just ran out of those seeds so I decided to order some online. my medium is organic potting soil with a perlite and peat moss mixture and for the most part up until the damage caused by the spider mites before getting it under control I had very fluent growth during veg,the three weeks it took me to rid myself of the pests and the damage initially done, growth stopped almost completely and is just now picking back up.they are very healthy completely female and no new pest damage whatsoever, but they don't seem to be thriving the way my last 4 grows did 3 weeks into 12/12.my usual nutrient feed for vegetative was organic fertilizer mix which has done me pretty well in the past I also continued that same mix all the way through flowering on my last 4 grows,but these two strains don't seem to like that organic nutrient mix in flowering I guess because it is a little high in nitrogen,the white widows worked fine with it,but not these.I am about two and a half weeks into 12 12 and I have just identified sex and chopped down six males and im left with three and three of each strain beautiful flowering ladies they are just very slow in growth and not as far along as they would have been had my growth not slowed (actually stopped completely during the 3 week battle with the pests)and don't seem to be flourishing as thick and abundant as my last four grows of the white widow did at this same point under all the same conditions!I would like any advice, I am kind of limited on money but would like to know what would be the best flowering nutrient mix cheap of cost to go with to increase my productivity and growth for the rest of my flowering stage so I can end up with at least a decent harvest.