Most non-coco specific nutrient systems will contain too much potassium for the media which will retain a rather large buffer of calcium and potassium. This is why Canna A+B includes so little Potassium in their formula. As a result you are going to find yourself using very little of the Advanced nutrients two part macro-nutrient system in coco and instead relying on Nitrogen, Calcium, Magnesium, and Phosphorus supplements to maintain the correct ratio of nutrients for coco fiber.
I have been using Canna for a while now, and it does require some P,K, and Mag supplements for flowering, but it veggz beautiful plants. Many people choose to add Cal-Mag to their mix in order to supplement additional Nitrogen and Calcium. I find this works well, but so does simply increasing the amounts of A+B used during veg.
CNS 17 Coco/Soil has a really great system with very ideal NPK, Ca, and Mg ratio's throughout the entire life of the plant when using their directions. CNS 17 Grow and Bloom is really all you need, though you can choose to add CNS 17 Ripe, and any number of other Botanicare products like Liquid Karma, Sweet, Hydroplex, Silica, and/or PureBlend.
After a good deal of time spent with Canna, and watching other growers using CNS 17 coco/soil Grow, Bloom, and Ripe... I think Botanicare has a superior system when it comes to cost, simplicity, and results.