Need suggestion on an additive or enhancer...35 days flowering

Hey guys, this is my first grow and I really wanna make sure I get some nice bud. Two of my four plants are pretty unhappy but the other two are thriving. I was looking for a suggestion to help increase bud size. I've looked at a few but most on here say to use them first few weeks of flowering. I'm currently feeding them 16 mls/gallon of Florabloom and about 10 mls/gallon flora micro as all my leaves have been yellowing and dying very early in flowering and I still can't figure out the problem.

Few pics from day 28 flowering...

gravity by humboldt countys own makes the bud dense..i use it at the 6th week..

for an overload of yield increase if the plants are between week 2-4 you can use phosphoload. i used that shit for the first time in my grow and the results were nuts!

Ok thanks, they are all at 35 days today so I'm looking for something to use from now to finish. I forgot to mention I'm feeding molasses as well but am not sure if it's doing anything. Strains are white widow (dark green ones) and northern lights( ones with light green and yellowing leaves.

they look ok plants mate. them tall ones are stealing the light from the plant at the bottom of the first photo tho. maybe try raise that one up..and if possible bend and tie some of the branches on the bigger plants..they are either real tall for whatever reason, or they are sativa. if they are sativa they will take longer to flower than the small plant which looks indica..if the little ones indica and it most probly is, your only half way through flowering if its an 8 weeker. theres plenty of time to fatten up on her own if she gets the light.

btw ive not used the nutes you use but they seem to be working imho..but if you want an addative canna pk13\14 is okay in soil at about week 3 and again at week 6..or canna boost is a better organic one..

good luck man and plus rep for the grow so far

i use gravity but im looking for more.. im leaning towards the botanicare hydroplex which has an npk ratio of .5-10-6 plus it has more than just a higher npk like humic, fulvic, & amino acids, & other good stuff as well. thats what sells me for a bloom booster. i checked on gh kool bloom, monster bloom, ff beastie bloom, & ginormous but im still sold on having more than just a higher npk number.

look into big bud powder in conjunction with a carb like carboload or bud candy. and you could always throw in some snow storm ultra as well. i've had good results with all 3 in soiless mix. in hydro i usually go for big bud and bud candy and then switch to overdrive the last few weeks before flush. i also foliar spray with dutch master saturator and folitech flower up until buds have formed.