I use flora blend. I use it up until late flowering. You can use it all the way threw, but I do not use much additives late in flower except a bloom booster and a sweetener (no real reason just my style, mainly to keep TDS down to make more room for a P-K booster). Flora blend is "organic based" and does not mess with ppm to much. After I add it, it adds about 50ppm to the res.
As for snowstorm I use Purple max. Same thing...
I am doing a test grow with it right now. Its in my sig. "Purple Diesel Medical Grow" Check that out for how I have been going about it. If I were you I would mix the snowstorm with the sweatner and feed it to the plants every so often.
I use flora clean when my substrate tds goes over 1000ppm (ecX500) It is good to use an agent such as flora clean for getting rid of salt build up. Much better than RO water. RO water has nothing in it. You want to use a flushing agent or a nutrient solution that is very mild when getting rid of salt build up. I am not sure the exact reason but I think it has to do with EC. You want something in the water to help atract mollecules. I do not know. It is explained in Georges Bible.
good luck.
If you ever go about only feeding snowstorm to a few plants and leaving a few test plants, let me know the differences.
Good Luck with those nutrients. Let me know how it goes. I kind of want to feed flora blend to only half my plants next grow to see the difference.
peace