I use the original but I have not tried the bloom yet. It's pricey but worth it IMO. I also use an Amino Acid and a Humic Acid from Kelp for less but I will give theirs a shot next time. Its been a hard lesson for me to learn but you cant do enough for roots. 

Now when I change the res I run nothing but root supplements for a day or 2 and then I go back and add nutrients. Its an easy way to do a root drench for hydro. Seems to work really well until I do something stupid