Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I would not get pre-mixed. Your tank might not need the ferts in the ratio of the mix.
Get each one separately. Start making small batches following a recipe like the Estimative Index. See how the tank responds and alter the recipe.
If you are running a low tech tank then fish food is probably supplying a fair amount of N, P and most traces, but is low in K, Fe and Ca.
If you are running a high tech tank then fish food is probably not supplying much fertiilzer. The plants are using it up and wanting more.
KNO3. Low tech: won't use much. High tech: use lots.
KH2PO4: Low tech: won't use much. High tech: Still won't use much, the dosing is low, but important. Don't skip it.
K2SO4: Low tech: This is the main source of K in a tank where you do not dose much KNO3. High tech: Won't use much. KNO3 is the main source of K. Might use some, so I would still get some.
CSM+B: Will use in both systems, but not much in low tech.
Chelated Iron: Will use in both systems.
GH booster: If your GH is low then you will use some at each water change. Check the tank through the week, and you might need to add some between water changes, if the plants and fish use enough of the minerals.