N, P, K - Nitrogen, Phosphorus and Potassium - the Macronutrients.
To 500 ml of distilled water add:
61 g (10.69 teaspoons, 3.63 tablespoons) Potassium nitrate (KNO3)
5.2 g (1 teaspoons) Potassium monophosphate (KP04)
10.8 g (2 teaspoons) Magnesium sulphate (MgSO4)
1.8 g (0.3 or 1/3 teaspoon) Potassium sulphate (KSO4)
3 times a week add 10 ml for a 20 gallon tank. Or 1-2 ml daily. Or 15 ml twice a week. This will add 30 ppm nitrate a week to a tank with corresponding correct proportions for the other macronutrients
Iron and trace elements. Use 71 grams (2.5 T) of Plantex CSM+B
to one liter of distilled water.
Use 1 cc per 2 gal to raise Fe 5.0 ppm. For example a 20 gal tank gets 10cc (two cupfuls)
Dose daily, biweekly or weekly depending on bioload. You will get to be able to recognize plant behavior to know when to add more. Some species such as Cryptocoryne require an absurd amount of iron in the water column.
(Diluted by half to the levels here Aug 6/07 rjs. Precipitates out otherwise.)
-- Richard Sexton, 2006
