don't buy the powders, they don't last nearly long enough. if you do buy one of the powders, get the coconut (it lasts longer), and go and buy a couple aloe plants.
coconut, as a mentioned, has cytokinins in it, which promote meristem growth and I think is a good trick to use in the first couple weeks of flower to help short/stocky plants that don't stretch up a lot put out that extra growth spurt. it also has potassium in it as well for bloom. ideally, you want the coconut water right from the coconut as it will be in its more natural form. if that's not available, i just buy a bottle of coconut water beverage (make sure it's only coconut water on ingredients list) and use that at 1/4c per gallon. of course, buy one for yourself too!
aloe is just all around awesome. full of enzymes, acts as a wetting agent helping soils absorb water better, and also has salicylic acid and in light doses (2 tbsp per gallon max of the clear pulp) helps induce flowering in plants. I've seen aloe make my plants pray so hard the leaves were practically vertical. I think it's important to not overdo the aloe dosage though, now that I have a shit ton of it i started just grabbing and mashing and overdoing it and i haven't been seeing the praying effect as much, i think it has to do with dosage. less is more as usual
. Oh yeah aloe is used as a cloning agent too (the salicylic acid) and works great! i'm sure you knew that already...