Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
What are the guaranteed analysis of the products you are using?
Plants need over a dozen elements to live.
If the products you are using do not contain all they need, or the elements are not in the right balance, then the plants won't grow.
What are the test results for the tank?
NO3, NO2, Ammonia
GH, KH, pH
any other tests you have.
Hydrogen, Oxygen, Carbon.
Seachem Excel is a source of carbon.
Nitrogen, Phosphorus, Potassium.
Fish food can supply a certain amount of N and P, but is lower in K.
Even if the fish food is supplying enough N and P, you would still have to dose K.
Calcium, Magnesium, Sulfur
If your tap water has a GH of at least 3 German degrees of hardness, then there might be enough Ca and Mg. If you want to dose a bit of GH booster you could. This would make sure the Ca and Mg levels are OK, just in case the tap water levels were not enough.
Fish food usually has enough S, and several fertilizers are supplied in the sulfate form. Not usually something you have to worry about.
Usually grouped with micros, but plants use more of it than the other micros, and fish food does not have very much. Even if you do not need to dose all the other micros, I would dose chelated iron.
All the other micros-
Approximately a dozen minerals that plants use in very small amounts. If overdosed they can be toxic. Fish food usually supplies enough of most of these, unless you are running a high tech tank.