Ferts during flowering?

This is the first time I've actually got buds indoors. They are looking OK but
seem to be taking a long time to fill in. The buds are there but they are not fat dense buds like in most big bud photos.I'm wondering if I need to add some ferts to make the buds get fat? I have several strains and at differnt grow periods. Some in veg. some in flower and also have seedlings. I remove the flowering plants after they get there 12 of light and put them in complete darkness outside the grow room. Flower side has 360 HPS conversion and some flouro's and a 400 watt MH on the veg. side. Watering when my finger inserted into pot as far down as can put it in comes out dry.Put at least 2-3 gals of water through each 3-5 gal. pot untill runs out clear. Have not added any thing but superthrive, 3 drops per gal. since flowering began. Temp is high and can only keep it at about 85- 98 %, but has always been that hot and plants seem to be healthy for the most part, they just do not flower out very fast!!!
Any info on how to lower the temp on a 0 dollar budget. I have a nice squirrel
fan/blower and two small oscallating fans.
Grow room is a 10' x 3' x 7' h. closet. Divided in half = 1 5' x 3' x 7'H. side for veg. and a 5' x 3' x 7'H. side for flowering.
Like I said I just move the flowering side out at night so the girls get 12 of complete darkness.
Please help!!!!!
I lost two very nice sativas from heat yesterday and do not want to lose anymore!
I have something to trade for a chiller fan if anyone is interested!
Peace to all and to all a good grow!
funkyjack

id dont think that superthrive is efficient enough for all your plants needs, specially in flowering. i suggest that u get some ALASKA FISH EMULSION along with MOR BLOOM FISH EMULSION, also made by ALASKA. They are cheap and they work well. And if ur plans are all sativa, or mostly sativa, that explains the buds not being dense. also, r u putting 2-3 gallons for every SINGLE plant, cause if so thats way tooo much water, use that much when u wanaa flush! try to keep your temp at 70-80 deg and humid at 30-50%.

Thanks bro, I do use a little bit of Bloom Buster, about 1/4 what it says on directions.
The watering I have always done this way.
I run a couple gallons water firs, then supethrive and very little bloom buster in the last water it gets.
I was told no nitrogen after 8 weeks and none at all while flowering ?
I am a long time outdoors grower, new to indoors, but am learning fast!
Thanks for the info,
peace to you and yours bro,
funkyjack