Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Are you still using the Seachem Flourish product line?
Flourish Comprehensive is trace minerals and a very low level of macros. This one is often simply called Flourish.
Flourish N, P, K are macros.
Flourish Excel is carbon.
As suggested above, you may need to increase the dosages.
If you are keeping a lot of fish, then the fish food may supply a certain amount of most nutrients, but generally is low in potassium, iron and calcium.
Your tap water can supply the Ca if the GH is above 3 German degrees of hardness, and you do enough water changes.
I would increase the dose of Flourish Potassium, and perhaps get some Flourish Iron. Comprehensive has iron, you could simply increase the dosing of this, instead of getting another product.