Hey SB
Good choice of nutrients, canna is supposed to be one of the best. I havent grown in coco personally but I think I can help you out with alternative additives that will be a little more cost effective. Canna's Rhizotonic is very similar to Advanced Nutrient's voodoo juice. Both are very expensive the AN is about 90.00 per liter, but i think it has a lower application rate. A cheaper alternative to the voodoo is Botanicare's aquashield (used to be hydroguard) it has 3 of the 6 strains of bacteria that AN has but it only costs around 25 bucks for a liter of the stuff. And as far as the Canna boost, I dont know much about it but I assume that it is supposed to work in a similar fashion as botanicare's Liquid Karma, or one of my favorites Advanced Nutrient's Nirvana (it has more humic acid) either way both should work out fine.
Also Big Bud liquid formulation is my strong reccomendation for your blooming agent. works very well in hydro,soil, and coco. and has proper P/K ratios (0-2-4 vs Canna's pk 13/14 or when diluted 0-2-2) Big Bud is specifically designed for weed. Apparently the plant doesn't require as much phosphorus as people used to use (pk13/14) but instead likes a lot of potassium, mg, calcium and surprisingly a decent amount of nitrogen (which Big Bud supplies in the form of 22 "L" or free amino acids). I know your trying to save money but I also think you should get one more additive for bloom. It is not essential however, you can use big bud until flush time. But I HIGHLY reccomend you pick up a liter of Overdrive for the last two weeks of flower before your flush. It is rediculous, it really does make your plants swell up in the final weeks which is where it normally gains the most weight anyway. Ive used it with much success. You dont need it but your plant will just have a faster motabolism in the last 2 weeks when it normally winds down. I have used both and they both work like a charm. I know it seems like I'm whoreing advanced here, but I thought those two deserved mentioning. Good luck!
