thats not enough, seachem flourish is trace with minimal amounts of n-p-k. it is intended to be used with seachem nitrogen, phosphate and potassium. check out seachems website for flourish comprehensive, it'll say the same thing that i just said.
here is a pic of nutrient def's
http://3.bp.blogspot.com/_cwbt2D65i...JcdLSqSf4/s1600-h/3591814040_bc03c264a5_o.jpg
are you having problems with green spot algae at all? it can be an indicator of low phosphate.
and yes its a key fert. n-p-k are called macro nutrients and trace minerals are micro nutrients