I've never used the stuff. I don't know the N-P-K, but it (the maxicrop liquid seaweed ad) does mention specifically "Also contains growth regulators which stimulate vigorous root development and plant growth". By stimulating growth, I'm guessing it's going to be fighting the plant's desire to bulk-up during flower.

Best way to find out is a side-by-side, but I'd only use it through the growth stage. :jointsmile:

p.s. Most bulking agents are molasses-derived. Provides calcium and a couple of micronutes. (my Fox Farms has pretty much all the micro's you'll need, though)