supernatural stay green

[green acres]

some of my larger fan leaves are yellowing already ( seems a bit early to me) they are at day 37 of flowering and look like they still have quite a ways to go. i know the yellowing is natural at the end. what i was wondering was, i have a sample of supernatural green stay. does it realy work to keep the leaves green. also i have given nutes around the 24 of june and just water since, they have been drinking alot because of high temps here, the room has been 30 to 32 with light on and 22 off, and it`s going to last a while. the mix was 10 ml`s of botanicare pro bloom to 1 gallon water. should i use this stuff now or waite till i hit them again with next nute mix witch will be in probably a few more days and at that time i will give them pro bloom, liquid karma, and cal-mag. being that it`s a sample bottle the info is limited as is thier site, says what it does but not realy how to mix or what`s in it besides nitrogen. any help or direction for reads would be great.
pic to follow.

[green acres]

i forgot it`s not just the bottom leaves it has started with the largest ones. thes were from neer the top of the plant.

[Racefan]

you haven't fed the plant for almost 2 weeks and you want to know why your leaves are yellowing? Jeeze! Think about it! The damn things hungry! Feed it!!!

[green acres]

actualy thats one week and thats why i wanted to know about that stuff cause it was feeding day. went and got some cal-mag. that with bloom and liquid karma, better now.